Shanhui Fan
Joseph and Hon Mai Goodman Professor of the School of Engineering and Professor, by courtesy, of Applied Physics
Electrical Engineering
Bio
Fan's research interests are in fundamental studies of nanophotonic structures, especially photonic crystals and meta-materials, and applications of these structures in energy and information technology applications
Academic Appointments
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Professor, Electrical Engineering
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Professor (By courtesy), Applied Physics
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Member, Bio-X
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Affiliate, Precourt Institute for Energy
Administrative Appointments
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Director, the Edward L. Ginzton Laboratory, Stanford University (2014 - 2021)
Honors & Awards
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Member, National Academy of Engineering (2024)
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R. W. Wood Prize, Optica (Formerly the Optical Society of America) (2022)
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Simons Investigator in Physics, Simons Foundation (2021)
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Vannevar Bush Faculty Fellowship, Department of Defense (2017)
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Fellow, IEEE (2010)
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Fellow, SPIE (2009)
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Fellow, American Physical Society (2008)
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Adolph Lomb Medal, Optical Society of America (2007)
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Award for Initiatives in Research, National Academy of Sciences (2007)
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Fellow, Optical Society of America (2007)
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David and Lucile Packard Fellowship in Science and Engineering, David and Lucile Packard Foundation (2003)
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Career Award, National Science Foundation (2002)
Boards, Advisory Committees, Professional Organizations
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Scientific Advisory Board, Max Planck Institute for the Science of Light (2022 - Present)
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Co-Founder, Skycool Systems (2016 - Present)
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Co-Founder, Flexcompute (2016 - Present)
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Associate Editor, Applied Physics Letters (2013 - 2019)
Professional Education
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PhD, MIT, Physics (1997)
2024-25 Courses
- Guided Waves
EE 236B (Win) - Nanophotonics
EE 336, MATSCI 346 (Aut) -
Independent Studies (10)
- Curricular Practical Training
APPPHYS 291 (Aut, Win, Spr) - Curricular Practical Training
PHYSICS 291 (Aut, Win, Spr) - Directed Studies in Applied Physics
APPPHYS 290 (Aut, Win, Spr) - Master's Thesis and Thesis Research
EE 300 (Aut, Win, Spr) - Research
PHYSICS 490 (Aut, Win, Spr) - Special Studies and Reports in Electrical Engineering
EE 191 (Aut, Win, Spr) - Special Studies and Reports in Electrical Engineering
EE 391 (Aut, Win, Spr) - Special Studies and Reports in Electrical Engineering (WIM)
EE 191W (Aut, Win, Spr) - Special Studies or Projects in Electrical Engineering
EE 190 (Aut, Win, Spr) - Special Studies or Projects in Electrical Engineering
EE 390 (Aut, Win, Spr)
- Curricular Practical Training
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Prior Year Courses
2023-24 Courses
- Guided Waves
EE 236B (Win) - Nanophotonics
EE 336, MATSCI 346 (Aut)
2022-23 Courses
- Guided Waves
EE 236B (Win) - Nanophotonics
EE 336, MATSCI 346 (Aut) - Optics and Electronics Seminar
APPPHYS 483 (Spr)
2021-22 Courses
- Nanophotonics
EE 336, MATSCI 346 (Aut)
- Guided Waves
Stanford Advisees
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Doctoral Dissertation Reader (AC)
Yi-Shiou Duh, Jason Herrmann, Chenkai Mao, Chance Ornelas-Skarin, Taha Rajabzadeh, Colin Yule -
Postdoctoral Faculty Sponsor
Cheng Guo, Aviv Karnieli, Dongha Kim, Eran Lustig, Charles Roques-Carmes, Heming Wang, Renwen Yu, Ming Zhou -
Doctoral Dissertation Advisor (AC)
Aivar Abrashuly, Dali Cheng, Olivia Long, Beicheng Lou, Yubin Park, Haiwen Wang, Janet Zhong -
Master's Program Advisor
Feifei Cheng, Alice Fontaine, Lucas Pabarcius -
Doctoral (Program)
Aivar Abrashuly, Dali Cheng, Anand Lalwani, Sydney Mason, Yubin Park, Taha Rajabzadeh, Yixuan Shao, Mo Wu, Qingqing Zhao
All Publications
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RCWA4D: Electromagnetic solver for layered structures with incommensurate periodicities
COMPUTER PHYSICS COMMUNICATIONS
2025; 306
View details for DOI 10.1016/j.cpc.2024.109356
View details for Web of Science ID 001308930700001
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Legume: A free implementation of the guided-mode expansion method for photonic crystal slabs
COMPUTER PHYSICS COMMUNICATIONS
2024; 304
View details for DOI 10.1016/j.cpc.2024.109286
View details for Web of Science ID 001263832200001
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On-chip multi-degree-of-freedom control of two-dimensional materials.
Nature
2024
Abstract
Two-dimensional materials (2DM) and their heterostructures offer tunable electrical and optical properties, primarily modifiable through electrostatic gating and twisting. Although electrostatic gating is a well-established method for manipulating 2DM, achieving real-time control over interfacial properties remains challenging in exploring 2DM physics and advanced quantum device technology1-6. Current methods, often reliant on scanning microscopes, are limited in their scope of application, lacking the accessibility and scalability of electrostatic gating at the device level. Here we introduce an on-chip platform for 2DM with in situ adjustable interfacial properties, using a microelectromechanical system (MEMS). This platform comprises compact and cost-effective devices with the ability of precise voltage-controlled manipulation of 2DM, including approaching, twisting and pressurizing actions. We demonstrate this technology by creating synthetic topological singularities, such as merons, in the nonlinear optical susceptibility of twisted hexagonal boron nitride (h-BN)7-10. A key application of this technology is the development of integrated light sources with real-time and wide-range tunable polarization. Furthermore, we predict a quantum analogue that can generate entangled photon pairs with adjustable entanglement properties. Our work extends the abilities of existing technologies in manipulating low-dimensional quantum materials and paves the way for new hybrid two- and three-dimensional devices, with promising implications in condensed-matter physics, quantum optics and related fields.
View details for DOI 10.1038/s41586-024-07826-x
View details for PubMedID 39169189
View details for PubMedCentralID 7717928
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Unitary control of partially coherent waves. I. Absorption
PHYSICAL REVIEW B
2024; 110 (3)
View details for DOI 10.1103/PhysRevB.110.035430
View details for Web of Science ID 001281048000001
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Strong Coupling and Single-Photon Nonlinearity in Free-Electron Quantum Optics
ACS PHOTONICS
2024
View details for DOI 10.1021/acsphotonics.4c00908
View details for Web of Science ID 001280929500001
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Unitary control of partially coherent waves. II. Transmission or reflection
PHYSICAL REVIEW B
2024; 110 (3)
View details for DOI 10.1103/PhysRevB.110.035431
View details for Web of Science ID 001281048000003
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Free-Space Beam Steering with Twisted Bilayer Photonic Crystal Slabs
ACS PHOTONICS
2024
View details for DOI 10.1021/acsphotonics.4c00736
View details for Web of Science ID 001280000400001
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One-dimensional non-Hermitian band structures as Riemann surfaces
PHYSICAL REVIEW A
2024; 110 (1)
View details for DOI 10.1103/PhysRevA.110.012209
View details for Web of Science ID 001272523400004
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Theory for Broadband Large-Area Purcell Enhancement
ACS PHOTONICS
2024; 11 (7): 2667-2672
View details for DOI 10.1021/acsphotonics.4c00438
View details for Web of Science ID 001271810800001
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Mode distribution impact on photonic crystal surface emitting laser performance
APL PHOTONICS
2024; 9 (7)
View details for DOI 10.1063/5.0199361
View details for Web of Science ID 001281643300001
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Topological winding guaranteed coherent orthogonal scattering
PHYSICAL REVIEW A
2024; 109 (6)
View details for DOI 10.1103/PhysRevA.109.L061503
View details for Web of Science ID 001259956100002
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Nanoscale optical nonreciprocity with nonlinear metasurfaces.
Nature communications
2024; 15 (1): 5077
Abstract
Optical nonreciprocity is manifested as a difference in the transmission of light for the opposite directions of excitation. Nonreciprocal optics is traditionally realized with relatively bulky components such as optical isolators based on the Faraday rotation, hindering the miniaturization and integration of optical systems. Here we demonstrate free-space nonreciprocal transmission through a metasurface comprised of a two-dimensional array of nanoresonators made of silicon hybridized with vanadium dioxide (VO2). This effect arises from the magneto-electric coupling between Mie modes supported by the resonator. Nonreciprocal response of the nanoresonators occurs without the need for external bias; instead, reciprocity is broken by the incident light triggering the VO2 phase transition for only one direction of incidence. Nonreciprocal transmission is broadband covering over 100 nm in the telecommunication range in the vicinity of λ = 1.5 µm. Each nanoresonator unit cell occupies only ~0.1 λ3 in volume, with the metasurface thickness measuring about half-a-micron. Our self-biased nanoresonators exhibit nonreciprocity down to very low levels of intensity on the order of 150 W/cm2 or a µW per nanoresonator. We estimate picosecond-scale transmission fall times and sub-microsecond scale transmission rise. Our demonstration brings low-power, broadband and bias-free optical nonreciprocity to the nanoscale.
View details for DOI 10.1038/s41467-024-49436-1
View details for PubMedID 38871743
View details for PubMedCentralID PMC11176174
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Mesoscopic non-Hermitian skin effect
PHYSICAL REVIEW A
2024; 109 (6)
View details for DOI 10.1103/PhysRevA.109.L061501
View details for Web of Science ID 001240301700008
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Light bullet generation via stimulated Brillouin scattering
APL PHOTONICS
2024; 9 (6)
View details for DOI 10.1063/5.0201756
View details for Web of Science ID 001253520900001
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Time-modulated near-field radiative heat transfer.
Proceedings of the National Academy of Sciences of the United States of America
2024; 121 (17): e2401514121
Abstract
Near-field radiative heat transfer has recently attracted increasing interests for its applications in energy technologies, such as thermophotovoltaics. Existing works, however, are restricted to time-independent systems. Here, we explore near-field radiative heat transfer between two bodies under time modulation by developing a rigorous fluctuational electrodynamics formalism. We demonstrate that time modulation can result in the enhancement, suppression, elimination, or reversal of radiative heat flow between the two bodies, and can be used to create a radiative thermal diode with an infinite contrast ratio, as well as a near-field radiative heat engine that pumps heat from the cold to the hot bodies. The formalism reveals a fundamental symmetry relation in the radiative heat transfer coefficients that underlies these effects. Our results indicate the significant capabilities of time modulation for managing nanoscale radiative heat flow.
View details for DOI 10.1073/pnas.2401514121
View details for PubMedID 38640346
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Nonreciprocal thermal photonics
NATURE PHOTONICS
2024
View details for DOI 10.1038/s41566-024-01409-y
View details for Web of Science ID 001200406200001
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Nanophotonic Heat Exchanger for Enhanced Near-Field Radiative Heat Transfer.
Nano letters
2024
Abstract
Increasing near-field radiative heat transfer between two bodies separated by a vacuum gap is crucial for enhancing the power density in radiative energy transport and conversion devices. However, the largest radiative heat transfer coefficient between two realistic materials at room temperature is limited to around 2000 W/(m2·K) for a gap of 100 nm. Here, analogous to conventional plate-fin heat exchangers based on convection, we introduce the concept of a nanophotonic heat exchanger, which enhances near-field radiative heat transfer using two bodies with interpenetrating gratings. Our calculations, based on rigorous fluctuational electrodynamics, show that the radiative heat transfer coefficient between the bodies separated by a 100 nm gap can significantly exceed 2000 W/(m2·K) by increasing the aspect ratios of the gratings. We develop a semianalytical heat transfer model that agrees well with the rigorous calculations for design optimization. Our work opens new opportunities for enhancing near-field radiative heat transfer between any materials.
View details for DOI 10.1021/acs.nanolett.4c00506
View details for PubMedID 38565218
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Universal and Ultrafast Quantum Computation Based on Free-Electron-Polariton Blockade
PRX QUANTUM
2024; 5 (1)
View details for DOI 10.1103/PRXQuantum.5.010339
View details for Web of Science ID 001187750200002
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Three-Dimensional Reconfigurable Optical Singularities in Bilayer Photonic Crystals.
Physical review letters
2024; 132 (7): 073804
Abstract
Metasurfaces and photonic crystals have revolutionized classical and quantum manipulation of light and opened the door to studying various optical singularities related to phases and polarization states. However, traditional nanophotonic devices lack reconfigurability, hindering the dynamic switching and optimization of optical singularities. This paper delves into the underexplored concept of tunable bilayer photonic crystals (BPhCs), which offer rich interlayer coupling effects. Utilizing silicon nitride-based BPhCs, we demonstrate tunable bidirectional and unidirectional polarization singularities, along with spatiotemporal phase singularities. Leveraging these tunable singularities, we achieve dynamic modulation of bound-state-in-continuum states, unidirectional guided resonances, and both longitudinal and transverse orbital angular momentum. Our work paves the way for multidimensional control over polarization and phase, inspiring new directions in ultrafast optics, optoelectronics, and quantum optics.
View details for DOI 10.1103/PhysRevLett.132.073804
View details for PubMedID 38427898
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Optical Tellegen metamaterial with spontaneous magnetization.
Nature communications
2024; 15 (1): 1293
Abstract
The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a number of groundbreaking phenomena connected to fundamental (e.g., electrodynamics of axion and relativistic matter) and applied physics (e.g., magnetless isolators). We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range. The metamaterial is formed by randomly oriented bi-material nanocylinders in a host medium. Each nanocylinder consists of a ferromagnet in a single-domain magnetic state and a high-permittivity dielectric operating near the magnetic Mie-type resonance. The proposed metamaterial requires no external magnetic bias and operates on the spontaneous magnetization of the nanocylinders. By leveraging the emerging magnetic Weyl semimetals, we further show how a giant bulk effective magnetoelectric effect can be achieved in a proposed metamaterial, exceeding that of natural materials by almost four orders of magnitude.
View details for DOI 10.1038/s41467-024-45225-y
View details for PubMedID 38346950
View details for PubMedCentralID 5440727
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Gauge-Flux-Induced Anti-Pt Phase Transitions for Extreme Control of Channel-Drop Tunneling
LASER & PHOTONICS REVIEWS
2024
View details for DOI 10.1002/lpor.202300458
View details for Web of Science ID 001147099100001
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Photonic Topological Spin Pump in Synthetic Frequency Dimensions.
Physical review letters
2024; 132 (3): 033803
Abstract
Reducing geometrical complexity while preserving desired wave properties is critical for proof-of-concept studies in wave physics, as evidenced by recent efforts to realize photonic synthetic dimensions, isospectrality, and hyperbolic lattices. Laughlin's topological pump, which elucidates quantum Hall states in cylindrical geometry with a radial magnetic field and a time-varying axial magnetic flux, is a prime example of these efforts. Here we propose a two-dimensional dynamical photonic system for the topological pumping of pseudospin modes by exploiting synthetic frequency dimensions. The system provides the independent control of pseudomagnetic fields and electromotive forces achieved by the interplay between mode-dependent and mode-independent gauge fields. To address the axial open boundaries and azimuthal periodicity of the system, we define the adjusted local Chern marker with rotating azimuthal coordinates, proving the nontrivial topology of the system. We demonstrate the adiabatic pumping for crosstalk-free frequency conversion with wave front molding. Our approach allows for reproducing Laughlin's thought experiment at room temperature with a scalable setup.
View details for DOI 10.1103/PhysRevLett.132.033803
View details for PubMedID 38307059
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Radiative cooling textiles using industry-standard particle-free nonporous micro-structured fibers
NANOPHOTONICS
2024
View details for DOI 10.1515/nanoph-2023-0650
View details for Web of Science ID 001141867500001
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Unitary Control of Photonic Absorption and Emission
SPIE-INT SOC OPTICAL ENGINEERING. 2024
View details for DOI 10.1117/12.3004842
View details for Web of Science ID 001211427500003
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Photonic Spin Hopfions and Monopole Loops.
Physical review letters
2023; 131 (26): 263801
Abstract
Spin textures with various topological orders are of great theoretical and practical interest. Hopfion, a spin texture characterized by a three-dimensional topological order was recently realized in electronic spin systems. Here, we show that monochromatic light can be structured such that its photonic spin exhibits a hopfion texture in the three-dimensional real space. We also provide ways to construct spin textures of arbitrary Hopf charges. When extending the system to four dimensions by introducing a parameter dimension, a new type of topological defect in the form of a monopole loop in photonic spin is encountered. Each point on the loop is a topological spin defect in three dimensions, and the loop itself carries quantized Hopf charges. Such photonic spin texture and defect may find application in control and sensing of nanoparticles, and optical generation of topological texture in motions of particles or fluids.
View details for DOI 10.1103/PhysRevLett.131.263801
View details for PubMedID 38215381
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Spectral routers for snapshot multispectral imaging
APPLIED PHYSICS LETTERS
2023; 123 (26)
View details for DOI 10.1063/5.0176587
View details for Web of Science ID 001134243900002
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Angle-selective thermal emitter for directional radiative cooling and heating
JOULE
2023; 7 (12)
View details for DOI 10.1016/j.joule.2023.10.013
View details for Web of Science ID 001142770900001
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Numerical and theoretical study of eigenenergy braids in two-dimensional photonic crystals
PHYSICAL REVIEW B
2023; 108 (19)
View details for DOI 10.1103/PhysRevB.108.195413
View details for Web of Science ID 001112330600012
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Hyperbolic Polaritonic Rulers Based on van der Waals α-MoO3 Waveguides and Resonators.
ACS nano
2023
Abstract
Low-dimensional, strongly anisotropic nanomaterials can support hyperbolic phonon polaritons, which feature strong light-matter interactions that can enhance their capabilities in sensing and metrology tasks. In this work, we report hyperbolic polaritonic rulers, based on microscale α-phase molybdenum trioxide (α-MoO3) waveguides and resonators suspended over an ultraflat gold substrate, which exhibit near-field polaritonic characteristics that are exceptionally sensitive to device geometry. Using scanning near-field optical microscopy, we show that these systems support strongly confined image polariton modes that exhibit ideal antisymmetric gap polariton dispersion, which is highly sensitive to air gap dimensions and can be described and predicted using a simple analytic model. Dielectric constants used for modeling are accurately extracted using near-field optical measurements of α-MoO3 waveguides in contact with the gold substrate. We also find that for nanoscale resonators supporting in-plane Fabry-Perot modes, the mode order strongly depends on the air gap dimension in a manner that enables a simple readout of the gap dimension with nanometer precision.
View details for DOI 10.1021/acsnano.3c08735
View details for PubMedID 37948673
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Surface Phonon Polariton-Mediated Near-Field Radiative Heat Transfer at Cryogenic Temperatures.
Physical review letters
2023; 131 (19): 196302
Abstract
Recent experiments, at room temperature, have shown that near-field radiative heat transfer (NFRHT) via surface phonon polaritons (SPhPs) exceeds the blackbody limit by several orders of magnitude. Yet, SPhP-mediated NFRHT at cryogenic temperatures remains experimentally unexplored. Here, we probe thermal transport in nanoscale gaps between a silica sphere and a planar silica surface from 77-300 K. These experiments reveal that cryogenic NFRHT has strong contributions from SPhPs and does not follow the T^{3} temperature (T) dependence of far-field thermal radiation. Our modeling based on fluctuational electrodynamics shows that the temperature dependence of NFRHT can be related to the confinement of heat transfer to two narrow frequency ranges and is well accounted for by a simple analytical model. These advances enable detailed NFRHT studies at cryogenic temperatures that are relevant to thermal management and solid-state cooling applications.
View details for DOI 10.1103/PhysRevLett.131.196302
View details for PubMedID 38000410
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Asymmetric phase modulation of light with parity-symmetry broken metasurfaces
OPTICA
2023; 10 (10): 1287-1294
View details for DOI 10.1364/OPTICA.495681
View details for Web of Science ID 001106457500002
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Singular topology of scattering matrices
PHYSICAL REVIEW B
2023; 108 (15)
View details for DOI 10.1103/PhysRevB.108.155418
View details for Web of Science ID 001087449300002
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Roadmap on spatiotemporal light fields
JOURNAL OF OPTICS
2023; 25 (9)
View details for DOI 10.1088/2040-8986/ace4dc
View details for Web of Science ID 001048607800001
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Colorful low-emissivity paints for space heating and cooling energy savings.
Proceedings of the National Academy of Sciences of the United States of America
2023; 120 (34): e2300856120
Abstract
Space heating and cooling consume ~13% of global energy every year. The development of advanced materials that promote energy savings in heating and cooling is gaining increasing attention. To thermally isolate the space of concern and minimize the heat exchange with the outside environment has been recognized as one effective solution. To this end, here, we develop a universal category of colorful low-emissivity paints to form bilayer coatings consisting of an infrared (IR)-reflective bottom layer and an IR-transparent top layer in colors. The colorful visual appearance ensures the aesthetical effect comparable to conventional paints. High mid-infrared reflectance (up to ~80%) is achieved, which is more than 10 times as conventional paints in the same colors, efficiently reducing both heat gain and loss from/to the outside environment. The high near-IR reflectance also benefits reducing solar heat gain in hot days. The advantageous features of these paints strike a balance between energy savings and penalties for heating and cooling throughout the year, providing a comprehensive year-round energy-saving solution adaptable to a wide variety of climatic zones. Taking a typical midrise apartment building as an example, the application of our colorful low-emissivity paints can realize positive heating, ventilation, and air conditioning energy saving, up to 27.24 MJ/m2/y (corresponding to the 7.4% saving ratio). Moreover, the versatility of the paint, along with its applicability to diverse surfaces of various shapes and materials, makes the paints extensively useful in a range of scenarios, including building envelopes, transportation, and storage.
View details for DOI 10.1073/pnas.2300856120
View details for PubMedID 37579165
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Experimental realization of convolution processing in photonic synthetic frequency dimensions.
Science advances
2023; 9 (32): eadi4956
Abstract
Convolution is an essential operation in signal and image processing and consumes most of the computing power in convolutional neural networks. Photonic convolution has the promise of addressing computational bottlenecks and outperforming electronic implementations. Performing photonic convolution in the synthetic frequency dimension, which harnesses the dynamics of light in the spectral degrees of freedom for photons, can lead to highly compact devices. Here, we experimentally realize convolution operations in the synthetic frequency dimension. Using a modulated ring resonator, we synthesize arbitrary convolution kernels using a predetermined modulation waveform with high accuracy. We demonstrate the convolution computation between input frequency combs and synthesized kernels. We also introduce the idea of an additive offset to broaden the kinds of kernels that can be implemented experimentally when the modulation strength is limited. Our work demonstrate the use of synthetic frequency dimension to efficiently encode data and implement computation tasks, leading to a compact and scalable photonic computation architecture.
View details for DOI 10.1126/sciadv.adi4956
View details for PubMedID 37566663
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Direct observation of the violation of Kirchhoff's law of thermal radiation
NATURE PHOTONICS
2023
View details for DOI 10.1038/s41566-023-01261-6
View details for Web of Science ID 001032246800001
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Experimental probe of twist angle-dependent band structure of on-chip optical bilayer photonic crystal.
Science advances
2023; 9 (28): eadh8498
Abstract
Recently, twisted bilayer photonic materials have been extensively used for creating and studying photonic tunability through interlayer couplings. While twisted bilayer photonic materials have been experimentally demonstrated in microwave regimes, a robust platform for experimentally measuring optical frequencies has been elusive. Here, we demonstrate the first on-chip optical twisted bilayer photonic crystal with twist angle-tunable dispersion and great simulation-experiment agreement. Our results reveal a highly tunable band structure of twisted bilayer photonic crystals due to moiré scattering. This work opens the door to realizing unconventional twisted bilayer properties and novel applications in optical frequency regimes.
View details for DOI 10.1126/sciadv.adh8498
View details for PubMedID 37436985
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Tunable magnetless optical isolation with twisted Weyl semimetals
NANOPHOTONICS
2023
View details for DOI 10.1515/nanoph-2023-0241
View details for Web of Science ID 001027235500001
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Exceptional points and non-Hermitian photonics at the nanoscale.
Nature nanotechnology
2023
Abstract
Exceptional points (EPs) arising in non-Hermitian systems have led to a variety of intriguing wave phenomena, and have been attracting increased interest in various physical platforms. In this Review, we highlight the latest fundamental advances in the context of EPs in various nanoscale systems, and overview the theoretical progress related to EPs, including higher-order EPs, bulk Fermi arcs and Weyl exceptional rings. We peek into EP-associated emerging technologies, in particular focusing on the influence of noise for sensing near EPs, improving the efficiency in asymmetric transmission based on EPs, optical isolators in nonlinear EP systems and novel concepts to implement EPs in topological photonics. We also discuss the constraints and limitations of the applications relying on EPs, and offer parting thoughts about promising ways to tackle them for advanced nanophotonic applications.
View details for DOI 10.1038/s41565-023-01408-0
View details for PubMedID 37386141
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Multi-dimensional band structure spectroscopy in the synthetic frequency dimension.
Light, science & applications
2023; 12 (1): 158
Abstract
The concept of synthetic dimensions in photonics provides a versatile platform in exploring multi-dimensional physics. Many of these physics are characterized by band structures in more than one dimensions. Existing efforts on band structure measurements in the photonic synthetic frequency dimension however are limited to either one-dimensional Brillouin zones or one-dimensional subsets of multi-dimensional Brillouin zones. Here we theoretically propose and experimentally demonstrate a method to fully measure multi-dimensional band structures in the synthetic frequency dimension. We use a single photonic resonator under dynamical modulation to create a multi-dimensional synthetic frequency lattice. We show that the band structure of such a lattice over the entire multi-dimensional Brillouin zone can be measured by introducing a gauge potential into the lattice Hamiltonian. Using this method, we perform experimental measurements of two-dimensional band structures of a Hermitian and a non-Hermitian Hamiltonian. The measurements reveal some of the general properties of point-gap topology of the non-Hermitian Hamiltonian in more than one dimensions. Our results demonstrate experimental capabilities to fully characterize high-dimensional physical phenomena in the photonic synthetic frequency dimension.
View details for DOI 10.1038/s41377-023-01196-1
View details for PubMedID 37369684
View details for PubMedCentralID PMC10300075
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Spectral phase singularity and topological behavior in perfect absorption
PHYSICAL REVIEW B
2023; 107 (24)
View details for DOI 10.1103/PhysRevB.107.L241403
View details for Web of Science ID 001015606800002
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Microring-based programmable coherent optical neural networks.
Optics express
2023; 31 (12): 18871-18887
Abstract
Coherent programmable integrated photonics circuits have shown great potential as specialized hardware accelerators for deep learning tasks, which usually involve the use of linear matrix multiplication and nonlinear activation components. We design, simulate and train an optical neural network fully based on microring resonators, which shows advantages in terms of device footprint and energy efficiency. We use tunable coupled double ring structures as the interferometer components for the linear multiplication layers and modulated microring resonators as the reconfigurable nonlinear activation components. We then develop optimization algorithms to train the direct tuning parameters such as applied voltages based on the transfer matrix method and using automatic differentiation for all optical components.
View details for DOI 10.1364/OE.492551
View details for PubMedID 37381317
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Jaynes-Cummings interaction between low-energy free electrons and cavity photons.
Science advances
2023; 9 (22): eadh2425
Abstract
The Jaynes-Cummings Hamiltonian is at the core of cavity quantum electrodynamics; however, it relies on bound-electron emitters fundamentally limited by the binding Coulomb potential. In this work, we propose theoretically a new approach to realizing the Jaynes-Cummings model using low-energy free electrons coupled to dielectric microcavities and exemplify several quantum technologies made possible by this approach. Using quantum recoil, a large detuning inhibits the emission of multiple consecutive photons, effectively transforming the free electron into a few-level system coupled to the cavity mode. We show that this approach can be used for generation of single photons, photon pairs, and even a quantum SWAP gate between a photon and a free electron, with unity efficiency and high fidelity. Tunable by their kinetic energy, quantum free electrons are inherently versatile emitters with an engineerable emission wavelength. Hence, they pave the way toward new possibilities for quantum interconnects between photonic platforms at disparate spectral regimes.
View details for DOI 10.1126/sciadv.adh2425
View details for PubMedID 37256955
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Inverse Design of Optical Switch Based on Bilevel Optimization Inspired by Meta-Learning
ACS PHOTONICS
2023
View details for DOI 10.1021/acsphotonics.3c00113
View details for Web of Science ID 001010294300001
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Detecting the relative phase between different frequency components of a photon using a three-level A atom coupled to a waveguide
PHYSICAL REVIEW A
2023; 107 (5)
View details for DOI 10.1103/PhysRevA.107.L051702
View details for Web of Science ID 001006608500001
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Experimental evaluation of digitally verifiable photonic computing for blockchain and cryptocurrency
OPTICA
2023; 10 (5): 552-560
View details for DOI 10.1364/OPTICA.476173
View details for Web of Science ID 000996342500003
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Universal embedding of a non-Hermitian reciprocal scattering optical system into a Hermitian time-reversal-invariant system
PHYSICAL REVIEW A
2023; 107 (5)
View details for DOI 10.1103/PhysRevA.107.053516
View details for Web of Science ID 001063964300005
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Closing the Collection on Photovoltaic Energy Conversion
PHYSICAL REVIEW APPLIED
2023; 19 (5)
View details for DOI 10.1103/PhysRevApplied.19.050001
View details for Web of Science ID 000996033900004
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Increasing the Q-Contrast in Large Photonic Crystal Slab Resonators Using Bound-States-in-Continuum
ACS PHOTONICS
2023
View details for DOI 10.1021/acsphotonics.3c00126
View details for Web of Science ID 000985514200001
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Experimentally realized in situ backpropagation for deep learning in photonic neural networks.
Science (New York, N.Y.)
2023; 380 (6643): 398-404
Abstract
Integrated photonic neural networks provide a promising platform for energy-efficient, high-throughput machine learning with extensive scientific and commercial applications. Photonic neural networks efficiently transform optically encoded inputs using Mach-Zehnder interferometer mesh networks interleaved with nonlinearities. We experimentally trained a three-layer, four-port silicon photonic neural network with programmable phase shifters and optical power monitoring to solve classification tasks using "in situ backpropagation," a photonic analog of the most popular method to train conventional neural networks. We measured backpropagated gradients for phase-shifter voltages by interfering forward- and backward-propagating light and simulated in situ backpropagation for 64-port photonic neural networks trained on MNIST image recognition given errors. All experiments performed comparably to digital simulations ([Formula: see text]94% test accuracy), and energy scaling analysis indicated a route to scalable machine learning.
View details for DOI 10.1126/science.ade8450
View details for PubMedID 37104594
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Majorization Theory for Unitary Control of Optical Absorption and Emission.
Physical review letters
2023; 130 (14): 146202
Abstract
Unitary control changes the absorption and emission of an object by transforming the external light modes. It is widely used and underlies coherent perfect absorption. Yet two basic questions remain unanswered: For a given object under unitary control, what absorptivity α, emissivity e, and their contrast δ=e-α are attainable? How to obtain a given α, e, or δ? We answer both questions using the mathematics of majorization. We show that unitary control can achieve perfect violation or preservation of Kirchhoff's law in nonreciprocal objects, and uniform absorption or emission for any object.
View details for DOI 10.1103/PhysRevLett.130.146202
View details for PubMedID 37084437
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Metasurface-based realization of photonic time crystals.
Science advances
2023; 9 (14): eadg7541
Abstract
Photonic time crystals are artificial materials whose electromagnetic properties are uniform in space but periodically vary in time. The synthesis of these materials and experimental observation of their physics remain very challenging because of the stringent requirement for uniform modulation of material properties in volumetric samples. In this work, we extend the concept of photonic time crystals to two-dimensional artificial structures-metasurfaces. We demonstrate that time-varying metasurfaces not only preserve key physical properties of volumetric photonic time crystals despite their simpler topology but also host common momentum bandgaps shared by both surface and free-space electromagnetic waves. On the basis of a microwave metasurface design, we experimentally confirmed the exponential wave amplification inside a momentum bandgap and the possibility to probe bandgap physics by external (free-space) excitations. The proposed metasurface serves as a straightforward material platform for realizing emerging photonic space-time crystals and as a realistic system for the amplification of surface-wave signals in future wireless communications.
View details for DOI 10.1126/sciadv.adg7541
View details for PubMedID 37018399
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Observation of Negative Effective Thermal Diffusion in Gold Films
ACS PHOTONICS
2023; 10 (4): 1150-1158
View details for DOI 10.1021/acsphotonics.2c01916
View details for Web of Science ID 000962908100001
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Efficient biphoton emission in semiconductors by single-photon recycling
PHYSICAL REVIEW A
2023; 107 (3)
View details for DOI 10.1103/PhysRevA.107.033521
View details for Web of Science ID 000959679900002
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Time reflection and refraction in synthetic frequency dimension
PHYSICAL REVIEW RESEARCH
2023; 5 (1)
View details for DOI 10.1103/PhysRevResearch.5.L012046
View details for Web of Science ID 000959351600002
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Moving media as photonic heat engine and pump
PHYSICAL REVIEW B
2023; 107 (11)
View details for DOI 10.1103/PhysRevB.107.115406
View details for Web of Science ID 000962465800001
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Manipulating Coherence of Near-Field Thermal Radiation in Time-Modulated Systems.
Physical review letters
2023; 130 (9): 096902
Abstract
We show that the spatial coherence of thermal radiation can be manipulated in time-modulated photonic systems supporting surface polaritons. We develop a fluctuational electrodynamics formalism for such systems to calculate the cross-spectral density tensor of the emitted thermal electromagnetic fields in the near-field regime. Our calculations indicate that, due to time-modulation, spatial coherence can be transferred between different frequencies, and correlations between different frequency components become possible. All these effects are unique to time-modulated systems. We also show that the decay rate of optical emitters can be controlled in the proximity of such time-modulated structure. Our findings open a promising avenue toward coherence control in thermal radiation, dynamical thermal imaging, manipulating energy transfer among thermal or optical emitters, efficient near-field radiative cooling, and engineering spontaneous emission rates of molecules.
View details for DOI 10.1103/PhysRevLett.130.096902
View details for PubMedID 36930900
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Neural network learning with photonics and for photonic circuit design
NANOPHOTONICS
2023
View details for DOI 10.1515/nanoph-2023-0123
View details for Web of Science ID 000941272900001
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Artificial Non-Abelian Lattice Gauge Fields for Photons in the Synthetic Frequency Dimension.
Physical review letters
2023; 130 (8): 083601
Abstract
Non-Abelian gauge fields give rise to nontrivial topological physics. Here we develop a scheme to create an arbitrary SU(2) lattice gauge field for photons in the synthetic frequency dimension using an array of dynamically modulated ring resonators. The photon polarization is taken as the spin basis to implement the matrix-valued gauge fields. Using a non-Abelian generalization of the Harper-Hofstadter Hamiltonian as a specific example, we show that the measurement of the steady-state photon amplitudes inside the resonators can reveal the band structures of the Hamiltonian, which show signatures of the underlying non-Abelian gauge field. These results provide opportunities to explore novel topological phenomena associated with non-Abelian lattice gauge fields in photonic systems.
View details for DOI 10.1103/PhysRevLett.130.083601
View details for PubMedID 36898123
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Thermally Responsive Hydrogels for Passive Temperature Regulation under Direct Sunlight
ADVANCED PHOTONICS RESEARCH
2023
View details for DOI 10.1002/adpr.202200253
View details for Web of Science ID 000928451700001
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Light control with Weyl semimetals
ELIGHT
2023; 3 (1)
View details for DOI 10.1186/s43593-022-00036-w
View details for Web of Science ID 001093205300001
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Quantum sensing of strongly coupled light-matter systems using free electrons.
Science advances
2023; 9 (1): eadd2349
Abstract
Strong coupling in light-matter systems is a central concept in cavity quantum electrodynamics and is essential for many quantum technologies. Especially in the optical range, full control of highly connected multi-qubit systems necessitates quantum coherent probes with nanometric spatial resolution, which are currently inaccessible. Here, we propose the use of free electrons as high-resolution quantum sensors for strongly coupled light-matter systems. Shaping the free-electron wave packet enables the measurement of the quantum state of the entire hybrid systems. We specifically show how quantum interference of the free-electron wave packet gives rise to a quantum-enhanced sensing protocol for the position and dipole orientation of a subnanometer emitter inside a cavity. Our results showcase the great versatility and applicability of quantum interactions between free electrons and strongly coupled cavities, relying on the unique properties of free electrons as strongly interacting flying qubits with miniscule dimensions.
View details for DOI 10.1126/sciadv.add2349
View details for PubMedID 36598994
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Power monitoring in a feedforward photonic network using two output detectors
NANOPHOTONICS
2023
View details for DOI 10.1515/nanoph-2022-0527
View details for Web of Science ID 000909801000001
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Response to comment on "Does non-reciprocity break the Shockley-Queisser limit in single-junction solar cells?" [Appl. Phys. Lett. 122, 016101 (2023)]
APPLIED PHYSICS LETTERS
2023; 122 (1)
View details for DOI 10.1063/5.0134492
View details for Web of Science ID 000908410500003
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Frequency Response Characteristics of High-Power Photonic Crystal Surface-Emitting Lasers
IEEE. 2023
View details for DOI 10.1109/IPC57732.2023.10360658
View details for Web of Science ID 001156890300154
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Unitary Control of Optical Absorption and Emission
IEEE. 2023
View details for DOI 10.1109/IPC57732.2023.10360602
View details for Web of Science ID 001156890300103
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Nonreciprocal Thermal Emission Using Spatiotemporal Modulation of Graphene
ACS PHOTONICS
2022
View details for DOI 10.1021/acsphotonics.2c01411
View details for Web of Science ID 000907748100001
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Floquet-Mie Theory for Time-Varying Dispersive Spheres
LASER & PHOTONICS REVIEWS
2022
View details for DOI 10.1002/lpor.202100683
View details for Web of Science ID 000905585800001
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Topological spin defects of light
OPTICA
2022; 9 (12): 1417-1423
View details for DOI 10.1364/OPTICA.474612
View details for Web of Science ID 000924077400013
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Tunable guided resonance in twisted bilayer photonic crystal.
Science advances
2022; 8 (48): eadd4339
Abstract
We experimentally demonstrate tunable guided resonance in twisted bilayer photonic crystals. Both the numerically and the experimentally obtained transmission spectra feature resonances with frequencies strongly dependent on the twist angle, as well as resonances with frequencies that are largely independent of the twist angle. These resonant features can be well understood with a simple analytic theory based on band folding. Our work illustrates the rich tunable resonance physics in twisted bilayer systems.
View details for DOI 10.1126/sciadv.add4339
View details for PubMedID 36449612
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Thermal photonics with broken symmetries
ELIGHT
2022; 2 (1)
View details for DOI 10.1186/s43593-022-00025-z
View details for Web of Science ID 001094623100001
-
Nonreciprocal Thermophotovoltaic Systems
ACS PHOTONICS
2022
View details for DOI 10.1021/acsphotonics.2c01308
View details for Web of Science ID 000886614300001
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Super-Large-Scale Hierarchically Porous Films Based on Self-Assembled Eye-Like Air Pores for High-Performance Daytime Radiative Cooling.
Small (Weinheim an der Bergstrasse, Germany)
2022: e2205091
Abstract
Metal-free polymer daytime radiative cooling coatings with hierarchical eye-like air pores are proposed and fabricated with a super-large-scale film-stretching method. The hierarchically porous film (HPF) can be further coated with polymethyl methacrylate (PMMA) micro-hemispheres, forming coated HPF (cHPF), which do not dramatically change the optical or thermal properties. The cHPF is slightly better with a lower solar absorptivity (2.4%) and a higher thermal emissivity over the atmospheric transparency window (90.1%). The low solar absorptivity is due to the strong scattering of the hierarchical eye-like air pores, while the molecular vibrations and the focusing effect of the PMMA micro-hemispheres contribute to the high emissivity. An average mid-day temperature reduction of 7.92 °C is achieved relative to the air temperature, and the average cooling power reaches 116.0 W m-2 , which are much better than the cooling performances of the commercial cooling cushion. During the day, the cHPF-covered simulated building is up to 6.47 and 4.84 °C cooler than the ambient and the white painted counterpart, respectively. The film is durable and resistant to chemical etching, and very promising to use globally, especially in warm and tropical regions.
View details for DOI 10.1002/smll.202205091
View details for PubMedID 36328709
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Nanophotonic detector array to enable direct thermal infrared vision.
Optics express
2022; 30 (21): 39222-39233
Abstract
Detection of infrared (IR) photons in a room-temperature IR camera is carried out by a two-dimensional array of microbolometer pixels which exhibit temperature-sensitive resistivity. When IR light coming from the far-field is focused onto this array, microbolometer pixels are heated up in proportion to the temperatures of the far-field objects. The resulting resistivity change of each pixel is measured via on-chip electronic readout circuit followed by analog to digital (A/D) conversion, image processing, and presentation of the final IR image on a separate information display screen. In this work, we introduce a new nanophotonic detector as a minimalist alternative to microbolometer such that the final IR image can be presented without using the components required for A/D conversion, image processing and display. In our design, the detector array is illuminated with visible laser light and the reflected light itself carries the IR image which can be directly viewed. We numerically demonstrate this functionality using a resonant waveguide grating structure made of typical materials such as silicon carbide, silicon nitride, and silica for which lithography techniques are well-developed. We clarify the requirements to tackle the issues of fabrication nonuniformities and temperature drifts in the detector array. We envision a potential near-eye display device for direct IR vision based on timely use of diffractive optical waveguides in augmented reality headsets and tunable visible laser sources. Our work indicates a way to achieve thermal IR vision for suitable use cases with lower cost, smaller form factor, and reduced power consumption compared to the existing thermal IR cameras.
View details for DOI 10.1364/OE.475296
View details for PubMedID 36258467
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Eigenvalue topology of non-Hermitian band structures in two and three dimensions
PHYSICAL REVIEW B
2022; 106 (16)
View details for DOI 10.1103/PhysRevB.106.L161401
View details for Web of Science ID 000882859900011
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Trajectory tracking through the control of non-equilibrium Casimir force
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2022; 289
View details for DOI 10.1016/j.jqsrt.2022.108281
View details for Web of Science ID 000813327300001
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Multidimensional Convolution Operation with Synthetic Frequency Dimensions in Photonics
PHYSICAL REVIEW APPLIED
2022; 18 (3)
View details for DOI 10.1103/PhysRevApplied.18.034088
View details for Web of Science ID 000866515900004
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Laser Cooling Assisted Thermal Management of Lightsails
ACS PHOTONICS
2022
View details for DOI 10.1021/acsphotonics.2c00889
View details for Web of Science ID 000861141100001
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Does non-reciprocity break the Shockley-Queisser limit in single-junction solar cells?
APPLIED PHYSICS LETTERS
2022; 121 (11)
View details for DOI 10.1063/5.0118129
View details for Web of Science ID 000859384700008
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Radiative-cooling-based nighttime electricity generation with power density exceeding 100 mW/m2.
iScience
2022; 25 (8): 104858
Abstract
The outer space (3 K) represents an important thermodynamic resource. It has been known for decades that at nighttime, a sky-facing thermal emitter radiating strongly within the atmospheric transparency window (8-13mum), can reach below the ambient temperature. In recent studies, thermoelectric generators were used to harness this temperature difference between the emitter and ambient to generate electricity. However, the demonstrated power density has been limited by parasitic thermal losses. Here we show that these parasitic losses can be reduced through thermal engineering. We present a simple model showing the optimum power density can be approached by controlling the relation between the emitter area and the thermal resistance of the thermoelectric generator. We show that the stacking of multiple thermoelectric generators is an effective way to approach this optimum. We experimentally demonstrate a generated electric power density >100 mW/m2, representing>2-fold improvement over the previous results for nighttime radiative cooling.
View details for DOI 10.1016/j.isci.2022.104858
View details for PubMedID 35996585
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Doping-driven topological polaritons in graphene/alpha-MoO3 heterostructures.
Nature nanotechnology
2022
Abstract
Control over charge carrier density provides an efficient way to trigger phase transitions and modulate the optoelectronic properties of materials. This approach can also be used to induce topological transitions in the optical response of photonic systems. Here we report a topological transition in the isofrequency dispersion contours of hybrid polaritons supported by a two-dimensional heterostructure consisting of graphene and alpha-phase molybdenum trioxide. By chemically changing the doping level of graphene, we observed that the topology of polariton isofrequency surfaces transforms from open to closed shapes as a result of doping-dependent polariton hybridization. Moreover, when the substrate was changed, the dispersion contour became dominated by flat profiles at the topological transition, thus supporting tunable diffractionless polariton propagation and providing local control over the optical contour topology. We achieved subwavelength focusing of polaritons down to 4.8% of the free-space light wavelength by using a 1.5-mum-wide silica substrate as an in-plane lens. Our findings could lead to on-chip applications in nanoimaging, optical sensing and manipulation of energy transfer at the nanoscale.
View details for DOI 10.1038/s41565-022-01185-2
View details for PubMedID 35982316
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A tandem radiative/evaporative cooler for weather-insensitive and high-performance daytime passive cooling.
Science advances
2022; 8 (32): eabq0411
Abstract
Radiative cooling and evaporative cooling with low carbon footprint are regarded as promising passive cooling strategies. However, the intrinsic limits of continuous water supply with complex systems for evaporative cooling, and restricted cooling power as well as the strict requirement of weather conditions for radiative cooling, hinder the scale of their practical applications. Here, we propose a tandem passive cooler composed of bilayer polymer that enables dual-functional passive cooling of radiation and evaporation. Specifically, the high reflectivity to sunlight and mid-infrared emissivity of this polymer film allows excellent radiative cooling performance, and its good atmospheric water harvesting property of underlayer ensures self-supply of water and high evaporative cooling power. Consequently, this tandem passive cooler overcomes the fundamental difficulties of radiative cooling and evaporative cooling and shows the applicability under various conditions of weather/climate. It is expected that this design can expand the practical application domain of passive cooling.
View details for DOI 10.1126/sciadv.abq0411
View details for PubMedID 35960798
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Scaling Challenges in High Power Photonic Crystal Surface-Emitting Lasers
IEEE JOURNAL OF QUANTUM ELECTRONICS
2022; 58 (4)
View details for DOI 10.1109/JQE.2022.3165314
View details for Web of Science ID 000837257900002
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Effect of choices of boundary conditions on the numerical efficiency of direct solutions of finite difference frequency domain systems with perfectly matched layers
OPTICS EXPRESS
2022; 30 (15): 26794-26806
View details for DOI 10.1364/OE.457233
View details for Web of Science ID 000828676200069
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Mirror symmetric on-chip frequency circulation of light
NATURE PHOTONICS
2022
View details for DOI 10.1038/s41566-022-01026-7
View details for Web of Science ID 000824862900001
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Roadmap on topological photonics
JOURNAL OF PHYSICS-PHOTONICS
2022; 4 (3)
View details for DOI 10.1088/2515-7647/ac4ee4
View details for Web of Science ID 000816867500001
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Reciprocity Constraints on Reflection.
Physical review letters
2022; 128 (25): 256101
Abstract
Reciprocity is a fundamental symmetry of Maxwell's equations. It is known that reciprocity imposes constraints on transmission, absorption, and emission. Here, we reveal reciprocity constraints on reflection. We determine the sets of all attainable reflection coefficients of n-port scattering matrices with prescribed singular values, both with and without assuming reciprocity. Their difference establishes reciprocity constraints and nonreciprocal behaviors. As an application, we examine the conditions for all-zero reflections. Our results deepen the understanding of reciprocity in optics.
View details for DOI 10.1103/PhysRevLett.128.256101
View details for PubMedID 35802447
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Creating boundaries along a synthetic frequency dimension.
Nature communications
2022; 13 (1): 3377
Abstract
Synthetic dimensions have garnered widespread interest for implementing high dimensional classical and quantum dynamics on low-dimensional geometries. Synthetic frequency dimensions, in particular, have been used to experimentally realize a plethora of bulk physics effects. However, in synthetic frequency dimension there has not been a demonstration of a boundary which is of paramount importance in topological physics due to the bulk-edge correspondence. Here we construct boundaries in the frequency dimension of dynamically modulated ring resonators by strongly coupling an auxiliary ring. We explore various effects associated with such boundaries, including confinement of the spectrum of light, discretization of the band structure, and the interaction of boundaries with one-way chiral modes in a quantum Hall ladder, which exhibits topologically robust spectral transport. Our demonstration of sharp boundaries fundamentally expands the capability of exploring topological physics, and has applications in classical and quantum information processing in synthetic frequency dimensions.
View details for DOI 10.1038/s41467-022-31140-7
View details for PubMedID 35697716
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Temporal modulation brings metamaterials into new era.
Light, science & applications
2022; 11 (1): 173
Abstract
Temporal modulations in photonics bring many exotic optical phenomena in the time dimension while metamaterials provide powerful ways in manipulating light in the spatial domain. The authors envision the connection, Floquet Metamaterials, may deliver novel opportunities in nanophotonics.
View details for DOI 10.1038/s41377-022-00870-0
View details for PubMedID 35672282
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Nonreciprocal infrared absorption via resonant magneto-optical coupling to InAs.
Science advances
2022; 8 (18): eabm4308
Abstract
Nonreciprocal elements are a vital building block of electrical and optical systems. In the infrared regime, there is a particular interest in structures that break reciprocity because their thermal absorptive (and emissive) properties should not obey the Kirchhoff thermal radiation law. In this work, we break time-reversal symmetry and reciprocity in n-type-doped magneto-optic InAs with a static magnetic field where light coupling is mediated by a guided-mode resonator structure, whose resonant frequency coincides with the epsilon-near-zero resonance of the doped indium arsenide. Using this structure, we observe the nonreciprocal absorptive behavior as a function of magnetic field and scattering angle in the infrared. Accounting for resonant and nonresonant optical scattering, we reliably model experimental results that break reciprocal absorption relations in the infrared. The ability to design these nonreciprocal absorbers opens an avenue to explore devices with unequal absorptivity and emissivity in specific channels.
View details for DOI 10.1126/sciadv.abm4308
View details for PubMedID 35522747
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Truncation-dependent PT phase transition for the edge states of a two-dimensional non-Hermitian system
PHYSICAL REVIEW B
2022; 105 (20)
View details for DOI 10.1103/PhysRevB.105.L201105
View details for Web of Science ID 000809495000002
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Adjoint Kirchhoff?s Law and General Symmetry Implications for All Thermal Emitters
PHYSICAL REVIEW X
2022; 12 (2)
View details for DOI 10.1103/PhysRevX.12.021023
View details for Web of Science ID 000796467700002
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Low-overhead distribution strategy for simulation and optimization of large-area metasurfaces
NPJ COMPUTATIONAL MATERIALS
2022; 8 (1)
View details for DOI 10.1038/s41524-022-00774-y
View details for Web of Science ID 000784578300004
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Violation of Kirchhoff's Law of Thermal Radiation with Space-Time Modulated Grating
ACS PHOTONICS
2022; 9 (4): 1157-1164
View details for DOI 10.1021/acsphotonics.1c01350
View details for Web of Science ID 000795895600009
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Design of Compact Meta-Crystal Slab for General Optical Convolution
ACS PHOTONICS
2022; 9 (4): 1358-1365
View details for DOI 10.1021/acsphotonics.1c02005
View details for Web of Science ID 000795895600030
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Few-particle scattering from localized quantum systems in spatially structured bosonic baths
QUANTUM
2022; 6
View details for Web of Science ID 000792765100001
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Observation of Weyl exceptional rings in thermal diffusion.
Proceedings of the National Academy of Sciences of the United States of America
2022; 119 (15): e2110018119
Abstract
SignificanceThermal diffusion is dissipative and strongly related to non-Hermitian physics. At the same time, non-Hermitian Weyl systems have spurred tremendous interest across photonics and acoustics. This correlation has been long ignored and hence shed little light upon the question of whether the Weyl exceptional ring (WER) in thermal diffusion could exist. Intuitively, thermal diffusion provides no real parameter dimensions, thus prohibiting a topological nature and WER. This work breaks this perception by imitating synthetic dimensions via two spatiotemporal advection pairs. The WER is achieved in thermal diffusive systems. Both surface-like and bulk states are demonstrated by coupling two WERs with opposite topological charges. These findings extend topological notions to diffusions and motivate investigation of non-Hermitian diffusive and dissipative control.
View details for DOI 10.1073/pnas.2110018119
View details for PubMedID 35377805
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Nighttime electric power generation at a density of 50 mW/m(2) via radiative cooling of a photovoltaic cell
APPLIED PHYSICS LETTERS
2022; 120 (14)
View details for DOI 10.1063/5.0085205
View details for Web of Science ID 000788794800002
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Subwavelength Bayer RGB color routers with perfect optical efficiency
NANOPHOTONICS
2022
View details for DOI 10.1515/nanoph-2022-0069
View details for Web of Science ID 000776298000001
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Tunable Frequency Filter Based on Twisted Bilayer Photonic Crystal Slabs
ACS PHOTONICS
2022; 9 (3): 800-805
View details for DOI 10.1021/acsphotonics.1c01263
View details for Web of Science ID 000776221600011
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Spectral emissivity modeling in multi-resonant systems using coupled-mode theory
OPTICS EXPRESS
2022; 30 (6): 9463-9472
Abstract
The ability to design multi-resonant thermal emitters is essential to the advancement of a wide variety of applications, including thermal management and sensing. These fields would greatly benefit from the development of more efficient tools for predicting the spectral response of coupled, multi-resonator systems. In this work, we propose a semi-analytical prediction tool based on coupled-mode theory. In our approach, a complex thermal emitter is fully described by a set of coupled-mode parameters, which can be straightforwardly calculated from simulations of unit cells containing single and double resonators. We demonstrate the accuracy of our method by predicting and optimizing spectral response in a coupled, multi-resonant system based on hBN ribbons. The approach described here can greatly reduce the computational overhead associated with spectral design tasks in coupled, multi-resonant systems.
View details for DOI 10.1364/OE.453275
View details for Web of Science ID 000768611900098
View details for PubMedID 35299373
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Topological Materials for Functional Optoelectronic Devices
ADVANCED FUNCTIONAL MATERIALS
2022
View details for DOI 10.1002/adfm.202110655
View details for Web of Science ID 000763537800001
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Topological dissipation in a time-multiplexed photonic resonator network
NATURE PHYSICS
2022
View details for DOI 10.1038/s41567-021-01492-w
View details for Web of Science ID 000756487100001
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Efficient method for accelerating line searches in adjoint optimization of photonic devices by combining Schur complement domain decomposition and Born series expansions
OPTICS EXPRESS
2022; 30 (4): 6413-6424
Abstract
A line search in a gradient-based optimization algorithm solves the problem of determining the optimal learning rate for a given gradient or search direction in a single iteration. For most problems, this is determined by evaluating different candidate learning rates to find the optimum, which can be expensive. Recent work has provided an efficient way to perform a line search with the use of the Shanks transformation of a Born series derived from the Lippman-Schwinger formalism. In this paper we show that the cost for performing such a line search can be further reduced with the use of the method of the Schur complement domain decomposition, which can lead to a 10-fold total speed-up resulting from the reduced number of iterations to convergence and reduced wall-clock time per iteration.
View details for DOI 10.1364/OE.451718
View details for Web of Science ID 000754931700138
View details for PubMedID 35209580
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Lineshape study of optical force spectra on resonant structures
OPTICS EXPRESS
2022; 30 (4): 6142-6160
Abstract
Understanding the frequency spectrum of the optical force is important for controlling and manipulating micro- and nano-scale objects using light. Spectral resonances of these objects can significantly influence the optical force spectrum. In this paper, we develop a theoretical formalism based on the temporal coupled-mode theory that analytically describes the lineshapes of force spectra and their dependencies on resonant scatterers for arbitrary incident wavefronts. We obtain closed-form formulae and discuss the conditions for achieving symmetric as well as asymmetric lineshapes, pertaining, respectively, to a Lorentzian and Fano resonance. The relevance of formalism as a design tool is exemplified for a conceptual scheme of the size-sorting mechanism of small particles, which plays a role in biomedical diagnosis.
View details for DOI 10.1364/OE.452764
View details for Web of Science ID 000754931700117
View details for PubMedID 35209557
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Internal transformations and internal symmetries in linear photonic systems
PHYSICAL REVIEW A
2022; 105 (2)
View details for DOI 10.1103/PhysRevA.105.023509
View details for Web of Science ID 000761176100013
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Polarization-Independent Isotropic Nonlocal Metasurfaces with Wavelength-Controlled Functionality
PHYSICAL REVIEW APPLIED
2022; 17 (2)
View details for DOI 10.1103/PhysRevApplied.17.024029
View details for Web of Science ID 000754633400005
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Photonics and thermodynamics concepts in radiative cooling
NATURE PHOTONICS
2022
View details for DOI 10.1038/s41566-021-00921-9
View details for Web of Science ID 000752149400002
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Concentrated radiative cooling and its constraint from reciprocity
OPTICS EXPRESS
2022; 30 (1): 275-285
View details for DOI 10.1364/OE.445544
View details for Web of Science ID 000738278500024
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Protecting ice from melting under sunlight via radiative cooling.
Science advances
2022; 8 (6): eabj9756
Abstract
As ice plays a critical role in various aspects of life, from food preservation to ice sports and ecosystem, it is desirable to protect ice from melting, especially under sunlight. The fundamental reason for ice melt under sunlight is related to the imbalanced energy flows of the incoming sunlight and outgoing thermal radiation. Therefore, radiative cooling, which can balance the energy flows without energy consumption, offers a sustainable approach for ice protection. Here, we demonstrate that a hierarchically designed radiative cooling film based on abundant and eco-friendly cellulose acetate molecules versatilely provides effective and passive protection to various forms/scales of ice under sunlight. This work provides inspiration for developing an effective, scalable, and sustainable route for preserving ice and other critical elements of ecosystems.
View details for DOI 10.1126/sciadv.abj9756
View details for PubMedID 35148187
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Prospects and applications of photonic neural networks
ADVANCES IN PHYSICS-X
2022; 7 (1)
View details for DOI 10.1080/23746149.2021.1981155
View details for Web of Science ID 000713018100001
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Flashing light with nanophotonics.
Science (New York, N.Y.)
2022; 375 (6583): 822-823
Abstract
Manipulation and enhancement of scintillation is achieved in nanophotonic structures.
View details for DOI 10.1126/science.abn8478
View details for PubMedID 35201880
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Universal Behavior of the Scattering Matrix Near Thresholds in Photonics.
Physical review letters
1800; 127 (27): 277401
Abstract
Scattering thresholds and their associated spectral square root branch points are ubiquitous in photonics. In this Letter, we show that the scattering matrix has a simple universal behavior near scattering thresholds. We use unitarity, reciprocity, and time-reversal symmetry to construct a two-parameter model for a two-port scattering matrix near a threshold. We demonstrate this universal behavior in three different optical systems, namely, a photonic crystal slab, a planar dielectric interface, and a junction between metallic waveguides of different widths.
View details for DOI 10.1103/PhysRevLett.127.277401
View details for PubMedID 35061418
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Thermodynamics of Light Management in Near-Field Thermophotovoltaics
PHYSICAL REVIEW APPLIED
2021; 16 (6)
View details for DOI 10.1103/PhysRevApplied.16.064063
View details for Web of Science ID 000739633200002
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Nonequilibrium lateral force and torque by thermally excited nonreciprocal surface electromagnetic waves
PHYSICAL REVIEW B
2021; 104 (24)
View details for DOI 10.1103/PhysRevB.104.245433
View details for Web of Science ID 000737276900010
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Coloured low-emissivity films for building envelopes for year-round energy savings
NATURE SUSTAINABILITY
2021
View details for DOI 10.1038/s41893-021-00836-x
View details for Web of Science ID 000734146900002
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Reaching the Ultimate Efficiency of Solar Energy Harvesting with a Nonreciprocal Multijunction Solar Cell.
Nano letters
1800
Abstract
The Landsberg limit represents the ultimate efficiency limit of solar energy harvesting. Reaching this limit requires the use of nonreciprocal elements. The existing device configurations for attaining the Landsberg limit, however, are very complicated. Here, we introduce the concept of a nonreciprocal multijunction solar cell and show that such a cell can reach the Landsberg limit in the idealized situation where an infinite number of layers are used. We also show that such a nonreciprocal multijunction cell outperforms a standard reciprocal multijunction cell for a finite number of layers. Our work significantly simplifies the device configuration required to reach the ultimate limit of solar energy conversion and points to a pathway toward using nonreciprocity to improve solar energy harvesting.
View details for DOI 10.1021/acs.nanolett.1c04288
View details for PubMedID 34939814
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Deterministic photonic quantum computation in a synthetic time dimension
OPTICA
2021; 8 (12): 1515-1523
View details for DOI 10.1364/OPTICA.424258
View details for Web of Science ID 000731870800003
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Nonreciprocal Thermal Emitters Using Metasurfaces with Multiple Diffraction Channels
PHYSICAL REVIEW APPLIED
2021; 16 (6)
View details for DOI 10.1103/PhysRevApplied.16.064001
View details for Web of Science ID 000727716900001
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Shockley-Queisser analysis of the temperature-efficiency correlation of solar cells in the presence of non- radiative heat transfer (vol 29, pg 27554, 2021)
OPTICS EXPRESS
2021; 29 (24): 39173
Abstract
This erratum corrects a typographical error in Fig. 2 of our published paper [Opt. Express29, 27554 (2021)10.1364/OE.434751].
View details for DOI 10.1364/OE.440880
View details for Web of Science ID 000722251200020
View details for PubMedID 34809286
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Phonon-induced anomalous gauge potential for photonic isolation in frequency space
OPTICA
2021; 8 (11): 1448-1457
View details for DOI 10.1364/OPTICA.429945
View details for Web of Science ID 000720968200015
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A perspective on the pathway towardfull wave simulation of large area metalenses (vol 119, 150502, 2021)<br>
APPLIED PHYSICS LETTERS
2021; 119 (20)
View details for DOI 10.1063/5.0076487
View details for Web of Science ID 000719676400005
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Subambient daytime radiative cooling textile based on nanoprocessed silk
NATURE NANOTECHNOLOGY
2021
Abstract
Decreasing energy consumption is critical to sustainable development. Because temperature regulation for human comfort consumes vast amounts of energy, substantial research efforts are currently directed towards developing passive personal thermal management techniques that cool the human body without any energy consumption1-9. Although various cooling textile designs have been proposed previously, textile-based daytime radiative cooling to a temperature below ambient has not been realized6-13. Silk, a natural protein fabric produced by moth caterpillars, is famous for its shimmering appearance and its cooling and comforting sensation on skin14-17. It has been recently recognized that silk, with its optical properties derived from its hierarchical microstructure, may represent a promising starting point for exploring daytime radiative cooling18-21. However, the intrinsic absorption of protein in the ultraviolet region prevents natural silk from achieving net cooling under sunlight. Here we explore the nanoprocessing of silk through a molecular bonding design and scalable coupling reagent-assisted dip-coating method, and demonstrate that nanoprocessed silk can achieve subambient daytime radiative cooling. Under direct sunlight (peak solar irradiance >900 W m-2) we observed a temperature of ~3.5 °C below ambient (for an ambient temperature of ~35 °C) for stand-alone nanoprocessed silks. We also observed a temperature reduction of 8 °C for a simulated skin when coated with nanoprocessed silk, compared with natural silk. This subambient daytime radiative cooling of nanoprocessed silk was achieved without compromising its wearability and comfort. This strategy of tailoring natural fabrics through scalable nanoprocessing techniques opens up new pathways to realizing thermoregulatory materials and provides an innovative way to sustainable energy.
View details for DOI 10.1038/s41565-021-00987-0
View details for Web of Science ID 000715703700003
View details for PubMedID 34750560
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Long-Range Directional Routing and Spatial Selection of High-Spin-Purity Valley Trion Emission in Monolayer WS2.
ACS nano
2021
Abstract
Valley-dependent excitation and emission in transition metal dichalcogenides (TMDCs) have recently emerged as a new avenue for optical data manipulation, quantum optical technologies, and chiral photonics. The valley-polarized electronic states can be optically addressed through photonic spin-orbit interaction of excitonic emission, typically with plasmonic nanostructures, but their performance is limited by the low quantum yield of neutral excitons in TMDC multilayers and the large Ohmic loss of plasmonic systems. Here, we demonstrate a valleytronic system based on the trion emission in high-quantum-yield WS2 monolayers chirally coupled to a low-loss microfiber. The integrated system uses the spin properties of the waveguided modes to achieve long-range directional routing of valley excitations and also provides an approach to selectively address valley-dependent emission from different spatial locations around the microfiber. This valleytronic interface can be integrated with fiber communication devices, allowing for merging valley polarization and chiral photonics as an alternative mechanism for optical information transport and manipulation in classical and quantum regimes.
View details for DOI 10.1021/acsnano.1c06955
View details for PubMedID 34730338
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Adaptive four-level modeling of laser cooling of solids
APPLIED PHYSICS LETTERS
2021; 119 (18)
View details for DOI 10.1063/5.0070422
View details for Web of Science ID 000716756400006
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Integrated cooling (i-Cool) textile of heat conduction and sweat transportation for personal perspiration management.
Nature communications
2021; 12 (1): 6122
Abstract
Perspiration evaporation plays an indispensable role in human body heat dissipation. However, conventional textiles tend to focus on sweat removal and pay little attention to the basic thermoregulation function of sweat, showing limited evaporation ability and cooling efficiency in moderate/profuse perspiration scenarios. Here, we propose an integrated cooling (i-Cool) textile with unique functional structure design for personal perspiration management. By integrating heat conductive pathways and water transport channels decently, i-Cool exhibits enhanced evaporation ability and high sweat evaporative cooling efficiency, not merely liquid sweat wicking function. In the steady-state evaporation test, compared to cotton, up to over 100% reduction in water mass gain ratio, and 3 times higher skin power density increment for every unit of sweat evaporation are demonstrated. Besides, i-Cool shows about 3°C cooling effect with greatly reduced sweat consumption than cotton in the artificial sweating skin test. The practical application feasibility of i-Cool design principles is well validated based on commercial fabrics. Owing to its exceptional personal perspiration management performance, we expect the i-Cool concept can provide promising design guidelines for next-generation perspiration management textiles.
View details for DOI 10.1038/s41467-021-26384-8
View details for PubMedID 34675199
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Space-Time Metasurfaces for Power Combining of Waves
ACS PHOTONICS
2021; 8 (10): 3034-3041
View details for DOI 10.1021/acsphotonics.1c00981
View details for Web of Science ID 000710954200028
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Editorial: Introducing the Collection on Photovoltaic Energy Conversion
PHYSICAL REVIEW APPLIED
2021; 16 (4)
View details for DOI 10.1103/PhysRevApplied.16.040001
View details for Web of Science ID 000708581900001
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Electron Pulse Compression with Optical Beat Note.
Physical review letters
2021; 127 (16): 164802
Abstract
Compressing electron pulses is important in many applications of electron beam systems. In this study, we propose to use optical beat notes to compress electron pulses. The beat frequency is chosen to match the initial electron pulse duration, which enables the compression of electron pulses with a wide range of durations. This functionality extends the optical control of electron beams, which is important in compact electron beam systems such as dielectric laser accelerators. We also find that the dominant frequency of the electron charge density changes continuously along its drift trajectory, which may open up new opportunities in coherent interaction between free electrons and quantum or classical systems.
View details for DOI 10.1103/PhysRevLett.127.164802
View details for PubMedID 34723609
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Electron Pulse Compression with Optical Beat Note
PHYSICAL REVIEW LETTERS
2021; 127 (16)
View details for DOI 10.1103/PhysRevLett.127.164802
View details for Web of Science ID 000707499800003
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A perspective on the pathway toward full wave simulation of large area metalenses
APPLIED PHYSICS LETTERS
2021; 119 (15)
View details for DOI 10.1063/5.0071245
View details for Web of Science ID 000754619000014
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Nontrivial point-gap topology and non-Hermitian skin effect in photonic crystals
PHYSICAL REVIEW B
2021; 104 (12)
View details for DOI 10.1103/PhysRevB.104.125416
View details for Web of Science ID 000704418600002
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Configurable Phase Transitions in a Topological Thermal Material.
Physical review letters
2021; 127 (10): 105901
Abstract
Diffusive nature of thermal transportation fundamentally restricts topological characteristics due to the absence of a sufficient parametric space with complex dimensionalities. Here, we create an orthogonal advection space with two advective pairs to reveal the unexplored topological transitions in thermal material. We demonstrate four types of configurable thermal phases, including the nontrivial dynamic-equilibrium distribution, nonchiral steplike pi-phase transition, and another two trivial profiles related to the anti-parity-time symmetry nature. Our findings provide a recipe for realizing a topologically robust thermal system under arbitrary perturbations.
View details for DOI 10.1103/PhysRevLett.127.105901
View details for PubMedID 34533332
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Violating Kirchhoff's Law of Thermal Radiation in Semitransparent Structures
ACS PHOTONICS
2021; 8 (8): 2417-2424
View details for DOI 10.1021/acsphotonics.1c00612
View details for Web of Science ID 000687190500028
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Inverse Design of Metasurfaces Based on Coupled-Mode Theory and Adjoint Optimization
ACS PHOTONICS
2021; 8 (8): 2265-2273
View details for DOI 10.1021/acsphotonics.1c00100
View details for Web of Science ID 000687190500011
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Generation of guided space-time wave packets using multilevel indirect photonic transitions in integrated photonics
PHYSICAL REVIEW RESEARCH
2021; 3 (3)
View details for DOI 10.1103/PhysRevResearch.3.033161
View details for Web of Science ID 000686919800001
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Shockley-Queisser analysis of the temperature-efficiency correlation of solar cells in the presence of non-radiative heat transfer
OPTICS EXPRESS
2021; 29 (17): 27554-27561
View details for DOI 10.1364/OE.434751
View details for Web of Science ID 000683895800103
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High-performance photonic transformers for DC voltage conversion.
Nature communications
2021; 12 (1): 4684
Abstract
Direct current (DC) converters play an essential role in electronic circuits. Conventional high-efficiency DC voltage converters, especially step-up type, rely on switching operation, where energy is periodically stored within and released from inductors and/or capacitors connected in a variety of circuit topologies. Since these energy storage components, especially inductors, are fundamentally difficult to scale down, miniaturization of switching converters proves challenging. Furthermore, the resulting switching currents produce significant electromagnetic noise. To overcome the limitations of switching converters, photonic transformers, where voltage conversion is achieved through light emission and detection processes, have been demonstrated. However, the demonstrated efficiency is significantly below that of the switching converter. Here we perform a detailed balance analysis and show that with a monolithically integrated design that enables efficient photon transport, the photonic transformer can operate with a near-unity conversion efficiency and high voltage conversion ratio. We validate the theory with a transformer constructed with off-the-shelf discrete components. Our experiment showcases near noiseless operation and a voltage conversion ratio that is significantly higher than obtained in previous photonic transformers. Our findings point to the possibility of a high-performance optical solution to miniaturizing DC power converters and improving the electromagnetic compatibility and quality of electrical power.
View details for DOI 10.1038/s41467-021-24955-3
View details for PubMedID 34344884
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Structured 3D linear space-time light bullets by nonlocal nanophotonics.
Light, science & applications
2021; 10 (1): 160
Abstract
We propose the generation of 3D linear light bullets propagating in free space using a single passive nonlocal optical surface. The nonlocal nanophotonics can generate space-time coupling without any need for bulky pulse-shaping and spatial modulation techniques. Our approach provides simultaneous control of various properties of the light bullets, including the external properties such as the group velocity and the propagation distance, and internal degrees of freedom such as the spin angular momentum and the orbital angular momentum.
View details for DOI 10.1038/s41377-021-00595-6
View details for PubMedID 34341327
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Engineering arbitrarily oriented spatiotemporal optical vortices using transmission nodal lines
OPTICA
2021; 8 (7): 966-971
View details for DOI 10.1364/OPTICA.426460
View details for Web of Science ID 000675721900004
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Controllable finite ultra-narrow quality-factor peak in a perturbed Dirac-cone band structure of a photonic-crystal slab
APPLIED PHYSICS LETTERS
2021; 119 (3)
View details for DOI 10.1063/5.0056243
View details for Web of Science ID 000674420200020
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Arbitrary synthetic dimensions via multiboson dynamics on a one-dimensional lattice
PHYSICAL REVIEW RESEARCH
2021; 3 (3)
View details for DOI 10.1103/PhysRevResearch.3.033069
View details for Web of Science ID 000674634400006
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Inverse Design of Plasma Metamaterial Devices for Optical Computing
PHYSICAL REVIEW APPLIED
2021; 16 (1)
View details for DOI 10.1103/PhysRevApplied.16.014023
View details for Web of Science ID 000678050500004
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Optimal two-photon excitation of bound states in non-Markovian waveguide QED
PHYSICAL REVIEW A
2021; 104 (1)
View details for DOI 10.1103/PhysRevA.104.013705
View details for Web of Science ID 000670697600007
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Isotropic topological second-order spatial differentiator operating in transmission mode
OPTICS LETTERS
2021; 46 (13): 3247-3250
Abstract
Differentiation has widespread applications, particularly in image processing for edge detection. Significant advances have been made in using nanophotonic structures and metamaterials to perform such operations. In particular, a recent work demonstrated a topological differentiator in which the transfer function exhibited a topological charge, making the differentiation operation robust to variations in operating conditions. The demonstrated topological differentiator, however, operates in reflection mode at off-normal incidence and is difficult to integrate into compact imaging systems. In this work, we design a topological differentiator that operates isotropically in transmission mode at normal incidence. The device exhibits an optical transfer function with a symmetry-protected topological charge of ±2 and performs second-order differentiation. Our work points to the potential of harnessing topological concepts for optical computing applications.
View details for DOI 10.1364/OL.430699
View details for Web of Science ID 000668963500063
View details for PubMedID 34197427
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Synthetic frequency dimensions in dynamically modulated ring resonators
APL PHOTONICS
2021; 6 (7)
View details for DOI 10.1063/5.0056359
View details for Web of Science ID 000691879600002
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Single Gyrotropic Particle as a Heat Engine
ACS PHOTONICS
2021; 8 (6): 1623-1629
View details for DOI 10.1021/acsphotonics.0c01920
View details for Web of Science ID 000664306400014
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Quantum Entanglement and Modulation Enhancement of Free-Electron-Bound-Electron Interaction
PHYSICAL REVIEW LETTERS
2021; 126 (23)
View details for DOI 10.1103/PhysRevLett.126.233402
View details for Web of Science ID 000661902600010
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Quantum Entanglement and Modulation Enhancement of Free-Electron-Bound-Electron Interaction.
Physical review letters
2021; 126 (23): 233402
Abstract
The modulation and engineering of the free-electron wave function bring new ingredients to the electron-matter interaction. We consider the dynamics of a free-electron passing by a two-level system fully quantum mechanically and study the enhancement of interaction from the modulation of the free-electron wave function. In the presence of resonant modulation of the free-electron wave function, we show that the electron energy loss and gain spectrum is greatly enhanced for a coherent initial state of the two-level system. Thus, a modulated electron can function as a probe of the atomic coherence. We further find that distantly separated two-level atoms can be entangled through interacting with the same free electron. Effects of modulation-induced enhancement can also be observed using a dilute beam of modulated electrons.
View details for DOI 10.1103/PhysRevLett.126.233402
View details for PubMedID 34170160
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Adjoint Method and Inverse Design for Nonlinear Nanophotonic Devices (vol 5, pg 4781, 2018)
ACS PHOTONICS
2021; 8 (5): 1505
View details for DOI 10.1021/acsphotonics.1c00396
View details for Web of Science ID 000655261600031
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Deep-Subwavelength Thermal Switch via Resonant Coupling in Monolayer Hexagonal Boron Nitride
PHYSICAL REVIEW APPLIED
2021; 15 (5)
View details for DOI 10.1103/PhysRevApplied.15.054002
View details for Web of Science ID 000656833300003
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Arbitrary linear transformations for photons in the frequency synthetic dimension.
Nature communications
2021; 12 (1): 2401
Abstract
Arbitrary linear transformations are of crucial importance in a plethora of photonic applications spanning classical signal processing, communication systems, quantum information processing and machine learning. Here, we present a photonic architecture to achieve arbitrary linear transformations by harnessing the synthetic frequency dimension of photons. Our structure consists of dynamically modulated micro-ring resonators that implement tunable couplings between multiple frequency modes carried by a single waveguide. By inverse design of these short- and long-range couplings using automatic differentiation, we realize arbitrary scattering matrices in synthetic space between the input and output frequency modes with near-unity fidelity and favorable scaling. We show that the same physical structure can be reconfigured to implement a wide variety of manipulations including single-frequency conversion, nonreciprocal frequency translations, and unitary as well as non-unitary transformations. Our approach enables compact, scalable and reconfigurable integrated photonic architectures to achieve arbitrary linear transformations in both the classical and quantum domains using current state-of-the-art technology.
View details for DOI 10.1038/s41467-021-22670-7
View details for PubMedID 33893284
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Publisher Correction: Topological optical differentiator.
Nature communications
2021; 12 (1): 2209
View details for DOI 10.1038/s41467-021-22493-6
View details for PubMedID 33828094
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Control of non-equilibrium Casimir force
APPLIED PHYSICS LETTERS
2021; 118 (14)
View details for DOI 10.1063/5.0043100
View details for Web of Science ID 000636953100001
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Effect of Coulomb interaction on the transient optical response of electrons in field-coupled quantum dots
PHYSICAL REVIEW A
2021; 103 (4)
View details for DOI 10.1103/PhysRevA.103.043504
View details for Web of Science ID 000646074500013
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Theory for Twisted Bilayer Photonic Crystal Slabs.
Physical review letters
2021; 126 (13): 136101
Abstract
We analyze scattering properties of twisted bilayer photonic crystal slabs through a high-dimensional plane wave expansion method. The method is applicable for arbitrary twist angles and does not suffer from the limitations of the commonly used supercell approximation. We show strongly tunable resonance properties of this system which can be accounted for semianalytically from a correspondence relation to a simpler structure. We also observe strongly tunable resonant chiral behavior in this system. Our work provides the theoretical foundation for predicting and understanding the rich optical physics of twisted multilayer photonic crystal systems.
View details for DOI 10.1103/PhysRevLett.126.136101
View details for PubMedID 33861130
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Wide wavelength-tunable narrow-band thermal radiation from moire patterns
APPLIED PHYSICS LETTERS
2021; 118 (13)
View details for DOI 10.1063/5.0047308
View details for Web of Science ID 000636372600002
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Photonic Chern insulators from two-dimensional atomic lattices interacting with a single surface plasmon polariton
PHYSICAL REVIEW B
2021; 103 (12)
View details for DOI 10.1103/PhysRevB.103.125423
View details for Web of Science ID 000646184800007
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Nondissipative non-Hermitian dynamics and exceptional points in coupled optical parametric oscillators
OPTICA
2021; 8 (3): 415–21
View details for DOI 10.1364/OPTICA.415569
View details for Web of Science ID 000631516600019
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Atomic-Scale Control of Coherent Thermal Radiation
ACS PHOTONICS
2021; 8 (3): 872–78
View details for DOI 10.1021/acsphotonics.0c01879
View details for Web of Science ID 000630366900025
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Transforming heat transfer with thermal metamaterials and devices
NATURE REVIEWS MATERIALS
2021
View details for DOI 10.1038/s41578-021-00283-2
View details for Web of Science ID 000628096200001
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Doubly-Resonant Photonic Crystal Cavities for Efficient Second-Harmonic Generation in III-V Semiconductors.
Nanomaterials (Basel, Switzerland)
2021; 11 (3)
Abstract
Second-order nonlinear effects, such as second-harmonic generation, can be strongly enhanced in nanofabricated photonic materials when both fundamental and harmonic frequencies are spatially and temporally confined. Practically designing low-volume and doubly-resonant nanoresonators in conventional semiconductor compounds is challenging owing to their intrinsic refractive index dispersion. In this work we review a recently developed strategy to design doubly-resonant nanocavities with low mode volume and large quality factor via localized defects in a photonic crystal structure. We built on this approach by applying an evolutionary optimization algorithm in connection with Maxwell equations solvers; the proposed design recipe can be applied to any material platform. We explicitly calculated the second-harmonic generation efficiency for doubly-resonant photonic crystal cavity designs in typical III-V semiconductor materials, such as GaN and AlGaAs, while targeting a fundamental harmonic at telecom wavelengths and fully accounting for the tensor nature of the respective nonlinear susceptibilities. These results may stimulate the realization of small footprint photonic nanostructures in leading semiconductor material platforms to achieve unprecedented nonlinear efficiencies.
View details for DOI 10.3390/nano11030605
View details for PubMedID 33670997
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Interaction of two-dimensional atomic lattices with a single surface plasmon polariton
PHYSICAL REVIEW A
2021; 103 (2)
View details for DOI 10.1103/PhysRevA.103.023716
View details for Web of Science ID 000619233800007
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Self-Focused Thermal Emission and Holography Realized by Mesoscopic Thermal Emitters
ACS PHOTONICS
2021; 8 (2): 497–504
View details for DOI 10.1021/acsphotonics.0c01487
View details for Web of Science ID 000621063700016
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Topological optical differentiator.
Nature communications
2021; 12 (1): 680
Abstract
Optical computing holds significant promise of information processing with ultrahigh speed and low power consumption. Recent developments in nanophotonic structures have generated renewed interests due to the prospects of performing analog optical computing with compact devices. As one prominent example, spatial differentiation has been demonstrated with nanophotonic structures and directly applied for edge detection in image processing. However, broadband isotropic two-dimensional differentiation, which is required in most imaging processing applications, has not been experimentally demonstrated yet. Here, we establish a connection between two-dimensional optical spatial differentiation and a nontrivial topological charge in the optical transfer function. Based on this connection, we experimentally demonstrate an isotropic two-dimensional differentiation with a broad spectral bandwidth, by using the simplest photonic device, i.e. a single unpatterned interface. Our work indicates that exploiting concepts from topological photonics can lead to new opportunities in optical computing.
View details for DOI 10.1038/s41467-021-20972-4
View details for PubMedID 33514708
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Nighttime Radiative Cooling for Water Harvesting from Solar Panels
ACS PHOTONICS
2021; 8 (1): 269–75
View details for DOI 10.1021/acsphotonics.0c01471
View details for Web of Science ID 000612567900029
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Exterior tuning and switching of non-equilibrium Casimir force
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2021; 38 (1): 151–58
View details for DOI 10.1364/JOSAB.405606
View details for Web of Science ID 000603408200020
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Topological complex-energy braiding of non-Hermitian bands.
Nature
2021; 598 (7879): 59-64
Abstract
Effects connected with the mathematical theory of knots1 emerge in many areas of science, from physics2,3 to biology4. Recent theoretical work discovered that the braid group characterizes the topology of non-Hermitian periodic systems5, where the complex band energies can braid in momentum space. However, such braids of complex-energy bands have not been realized or controlled experimentally. Here, we introduce a tight-binding lattice model that can achieve arbitrary elements in the braid group of two strands 𝔹2. We experimentally demonstrate such topological complex-energy braiding of non-Hermitian bands in a synthetic dimension6,7. Our experiments utilize frequency modes in two coupled ring resonators, one of which undergoes simultaneous phase and amplitude modulation. We observe a wide variety of two-band braiding structures that constitute representative instances of links and knots, including the unlink, the unknot, the Hopf link and the trefoil. We also show that the handedness of braids can be changed. Our results provide a direct demonstration of the braid-group characterization of non-Hermitian topology and open a pathway for designing and realizing topologically robust phases in open classical and quantum systems.
View details for DOI 10.1038/s41586-021-03848-x
View details for PubMedID 34616054
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Photonic Modal Circulator Using Temporal Refractive-Index Modulation with Spatial Inversion Symmetry.
Physical review letters
2021; 126 (19): 193901
Abstract
It has been demonstrated that dynamic refractive-index modulation, which breaks time-reversal symmetry, can be used to create on-chip nonreciprocal photonic devices. In order to achieve amplitude nonreciprocity, all such devices moreover require modulations that break spatial symmetries, which adds complexity in implementations. Here we introduce a modal circulator, which achieves amplitude nonreciprocity through a circulation motion among three modes. We show that such a circulator can be achieved in a dynamically modulated structure that preserves mirror symmetry, and as a result can be implemented using only a single standing-wave modulator, which significantly simplifies the implementation of dynamically modulated nonreciprocal devices. We also prove that in terms of the number of modes involved in the transport process, the modal circulator represents the minimum configuration in which complete amplitude nonreciprocity can be achieved while preserving spatial symmetry.
View details for DOI 10.1103/PhysRevLett.126.193901
View details for PubMedID 34047603
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Quantum entanglement and modulation enhancement of free-electron-bound-electron interaction
IEEE. 2021
View details for Web of Science ID 000831479800153
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Teleportation-Based Photonic Quantum Computing Using a Single Controllable Qubit
IEEE. 2021
View details for Web of Science ID 000831479800345
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Photonic arbitrary linear transformations in the frequency synthetic dimension
IEEE. 2021
View details for Web of Science ID 000831479802252
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Fabrication of Photonic Crystal Surface Emitting Lasers (PCSELs) by Epitaxial Regrowth
IEEE. 2021
View details for Web of Science ID 000831479801152
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Photonic Topological Dissipation in Time-Multiplexed Resonator Networks
IEEE. 2021
View details for Web of Science ID 000831479803034
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Manipulating Single Surface Plasmon Polariton via Tailored Atom-Photon Interaction
IEEE. 2021
View details for Web of Science ID 000831479801295
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Photonic modal circulator using dynamic modulation with mirror symmetry
IEEE. 2021
View details for Web of Science ID 000831479801260
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Design of Nighttime Power Generation System to Optimally Utilize Outer Space Darkness
IEEE. 2021
View details for Web of Science ID 000831479801422
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Photonic Meron Spin Texture in Momentum Space
IEEE. 2021
View details for Web of Science ID 000831479801264
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Experimental Demonstration of Dynamic Band Structure Measurement along a Synthetic Dimension
IEEE. 2021
View details for Web of Science ID 000831479802172
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Design principles of apodized grating couplers
IEEE. 2021
View details for Web of Science ID 000831479801202
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Arbitrary control and direct measurement of topological windings of a non-Hermitian band
IEEE. 2021
View details for Web of Science ID 000831479801305
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Generating arbitrary topological windings of a non-Hermitian band.
Science (New York, N.Y.)
2021; 371 (6535): 1240–45
Abstract
The nontrivial topological features in the energy band of non-Hermitian systems provide promising pathways to achieve robust physical behaviors in classical or quantum open systems. A key topological feature of non-Hermitian systems is the nontrivial winding of the energy band in the complex energy plane. We provide experimental demonstrations of such nontrivial winding by implementing non-Hermitian lattice Hamiltonians along a frequency synthetic dimension formed in a ring resonator undergoing simultaneous phase and amplitude modulations, and by directly characterizing the complex band structures. Moreover, we show that the topological winding can be controlled by changing the modulation waveform. Our results allow for the synthesis and characterization of topologically nontrivial phases in nonconservative systems.
View details for DOI 10.1126/science.abf6568
View details for PubMedID 33737483
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Dynamic band structure measurement in the synthetic space
SCIENCE ADVANCES
2021; 7 (2)
Abstract
Band structure theory plays an essential role in exploring physics in both solid-state systems and photonics. Here, we demonstrate a direct experimental measurement of the dynamic band structure in a synthetic space including the frequency axis of light, realized in a ring resonator under near-resonant dynamic modulation. This synthetic lattice exhibits the physical picture of the evolution of the wave vector reciprocal to the frequency axis in the band structure, analogous to a one-dimensional lattice under an external force. We experimentally measure the trajectories of the dynamic band structure by selectively exciting the band with a continuous wave source with its frequency scanning across the entire energy regime of the band. Our results not only provide a new perspective for exploring the dynamics in fundamental physics of solid-state and photonic systems with the concept of the synthetic dimension but also enable great capability in band structure engineering in photonics.
View details for DOI 10.1126/sciadv.abe4335
View details for Web of Science ID 000606331400044
View details for PubMedID 33524000
View details for PubMedCentralID PMC7793575
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Integrated thin-film lithium niobate non-reciprocal circulator
IEEE. 2021
View details for Web of Science ID 000831479801039
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Inverse design of relativistic lightsail for efficient propulsion
IEEE. 2021
View details for Web of Science ID 000831479802056
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Scattering of a single plasmon polariton by multiple atoms for in-plane control of light
NANOPHOTONICS
2021; 10 (1): 579–87
View details for DOI 10.1515/nanoph-2020-0340
View details for Web of Science ID 000597359300046
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Three-Dimensional Printable Nanoporous Polymer Matrix Composites for Daytime Radiative Cooling.
Nano letters
2021
Abstract
Daytime radiative cooling presents an exciting new strategy for combating global warming, because it can passively cool buildings by reflecting sunlight and utilizing the infrared atmospheric window to eject heat into outer space. Recent progress with novel material designs showed promising subambient cooling performance under direct sunlight. However, large-scale implementation of radiative cooling technologies is still limited by the high-cost and complex fabrication. Here, we develop a nanoporous polymer matrix composite (PMC) to enable rapid production and cost reduction using commercially available polymer processing techniques, such as molding, extrusion, and 3D printing. With a high solar reflectance of 96.2% and infrared emissivity > 90%, the nanoporous PMC achieved a subambient temperature drop of 6.1 °C and cooling power of 85 W/m2 under direct sunlight, which are comparable to the state-of-the-art. This work offers great promise to make radiative cooling technologies more viable for saving energy and reducing emissions in building cooling applications.
View details for DOI 10.1021/acs.nanolett.0c04810
View details for PubMedID 33464912
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Nonreciprocity in Bianisotropic Systems with Uniform Time Modulation.
Physical review letters
2020; 125 (26): 266102
Abstract
Physical systems with material properties modulated in time provide versatile routes for designing magnetless nonreciprocal devices. Traditionally, nonreciprocity in such systems is achieved exploiting both temporal and spatial modulations, which inevitably requires a series of time-modulated elements distributed in space. In this Letter, we introduce a concept of bianisotropic time-modulated systems capable of nonreciprocal wave propagation at the fundamental frequency and based on uniform, solely temporal material modulations. In the absence of temporal modulations, the considered bianisotropic systems are reciprocal. We theoretically explain the nonreciprocal effect by analyzing wave propagation in an unbounded bianisotropic time-modulated medium. The effect stems from temporal modulation of spatial dispersion effects which to date were not taken into account in previous studies based on the local-permittivity description. We propose a circuit design of a bianisotropic metasurface that can provide phase-insensitive isolation and unidirectional amplification.
View details for DOI 10.1103/PhysRevLett.125.266102
View details for PubMedID 33449712
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Nonreciprocity in Bianisotropic Systems with Uniform Time Modulation
PHYSICAL REVIEW LETTERS
2020; 125 (26)
View details for DOI 10.1103/PhysRevLett.125.266102
View details for Web of Science ID 000600849400009
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Inference in artificial intelligence with deep optics and photonics.
Nature
2020; 588 (7836): 39–47
Abstract
Artificial intelligence tasks across numerous applications require accelerators for fast and low-power execution. Optical computing systems may be able to meet these domain-specific needs but, despite half a century of research, general-purpose optical computing systems have yet to mature into a practical technology. Artificial intelligence inference, however, especially for visual computing applications, may offer opportunities for inference based on optical and photonic systems. In this Perspective, we review recent work on optical computing for artificial intelligence applications and discuss its promise and challenges.
View details for DOI 10.1038/s41586-020-2973-6
View details for PubMedID 33268862
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Radiative Thermal Router Based on Tunable Magnetic Weyl Semimetals
ACS PHOTONICS
2020; 7 (11): 3257–63
View details for DOI 10.1021/acsphotonics.0c01376
View details for Web of Science ID 000592916800035
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Scalable and hierarchically designed polymer film as a selective thermal emitter for high-performance all-day radiative cooling.
Nature nanotechnology
2020
Abstract
Traditional cooling systems consume tremendous amounts of energy and thus aggravate the greenhouse effect1,2. Passive radiative cooling, dissipating an object's heat through an atmospheric transparency window (8-13mum) to outer space without any energy consumption, has attracted much attention3-9. The unique feature of radiative cooling lies in the high emissivity in the atmospheric transparency window through which heat can be dissipated to the universe. Therefore, for achieving high cooling performance, the design and fabrication of selective emitters, with emission strongly dominant in the transparency window, is of essential importance, as such spectral selection suppresses parasitic absorption from the surrounding thermal radiation. Recently, various materials and structures with tailored spectrum responses have been investigated to achieve the effect of daytime radiative cooling6-8,10-15. However, most of the radiative cooling materials reported possess broad-band absorption/emission covering the whole mid-infrared wavelength11-15. Here we demonstrate that a hierarchically designed polymer nanofibre-based film, produced by a scalable electrostatic spinning process, enables selective mid-infrared emission, effective sunlight reflection and therefore excellent all-day radiative cooling performance. Specifically, the C-O-C (1,260-1,110cm-1) and C-OH (1,239-1,030cm-1) bonding endows the selective emissivity of 78% in 8-13mum wavelength range, and the design of nanofibres with a controlled diameter allows for a high reflectivity of 96.3% in 0.3-2.5mum wavelength range. As a result, we observe ~3°C cooling improvement of this selective thermal emitter as compared to that of a non-selective emitter at night, and 5°C sub-ambient cooling under sunlight. The impact of this hierarchically designed selective thermal emitter on alleviating global warming and temperature regulating an Earth-like planet is also analysed, with a significant advantage demonstrated. With its excellent cooling performance and a scalable process, this hierarchically designed selective thermal emitter opens a new pathway towards large-scale applications of all-day radiative cooling materials.
View details for DOI 10.1038/s41565-020-00800-4
View details for PubMedID 33199884
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Operating modes of dual-grating dielectric laser accelerators
PHYSICAL REVIEW ACCELERATORS AND BEAMS
2020; 23 (11)
View details for DOI 10.1103/PhysRevAccelBeams.23.114001
View details for Web of Science ID 000598051300001
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Beating absorption in solid-state high harmonics
COMMUNICATIONS PHYSICS
2020; 3 (1)
View details for DOI 10.1038/s42005-020-00472-5
View details for Web of Science ID 000588103100005
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Integrated Nonreciprocal Photonic Devices With Dynamic Modulation
PROCEEDINGS OF THE IEEE
2020; 108 (10): 1759–84
View details for DOI 10.1109/JPROC.2020.3023959
View details for Web of Science ID 000574742200004
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Tutorial on Electromagnetic Nonreciprocity and its Origins
PROCEEDINGS OF THE IEEE
2020; 108 (10): 1684–1727
View details for DOI 10.1109/JPROC.2020.3012381
View details for Web of Science ID 000574742200002
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Design of a multichannel photonic crystal dielectric laser accelerator
PHOTONICS RESEARCH
2020; 8 (10): 1586–98
View details for DOI 10.1364/PRJ.394127
View details for Web of Science ID 000577372300009
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Doubly resonant second-harmonic generation of a vortex beam from a bound state in the continuum
OPTICA
2020; 7 (9): 1126–32
View details for DOI 10.1364/OPTICA.396408
View details for Web of Science ID 000575440600013
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Squeeze free space with nonlocal flat optics
OPTICA
2020; 7 (9): 1133–38
View details for DOI 10.1364/OPTICA.392978
View details for Web of Science ID 000575440600014
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Inverse Design of Lightweight Broadband Reflector for Relativistic Lightsail Propulsion
ACS PHOTONICS
2020; 7 (9): 2350–55
View details for DOI 10.1021/acsphotonics.0c00768
View details for Web of Science ID 000573377300005
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Creating an Eco-Friendly Building Coating with Smart Subambient Radiative Cooling.
Advanced materials (Deerfield Beach, Fla.)
2020: e1906751
Abstract
Subambient daytime radiative cooling (SDRC) provides a promising electricity- and cryogen-free pathway for global energy-efficiency. However, current SDRC systems require stringent surface designs, which are neither cost-effective nor eco-friendly, to selectively emit thermal radiation to outer space and simultaneously maximize solar reflectance. Here, a generic method is developed to upgrade the conventional building-coating materials with a peculiar self-adaptive SDRC effect through combining particle scattering, sunlight-excited fluorescence, and mid-infrared broadband radiation. It is also theoretically proved that heat exchange with the sky can eliminate the use of resonant microstructures and noble metal mirrors in conventional SDRC, and also leads to enhanced daytime cooling yet suppressed nighttime overcooling. When exposed to direct sunlight, the upgraded coating over an aluminum plate can achieve 6 °C (7 °C on a scale-model building) below the ambient temperature under a solar intensity of 744 W m-2 (850 W m-2 ), yielding a cooling power of 84.2 W m-2 . The results pave the way for practical large-scale applications of high-performance SDRC for human thermal comfort in buildings.
View details for DOI 10.1002/adma.201906751
View details for PubMedID 32924184
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Analytic and geometric properties of scattering from periodically modulated quantum-optical systems
PHYSICAL REVIEW A
2020; 102 (3)
View details for DOI 10.1103/PhysRevA.102.033707
View details for Web of Science ID 000570300500018
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Parallel Programming of an Arbitrary Feedforward Photonic Network
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2020; 26 (5)
View details for DOI 10.1109/JSTQE.2020.2997849
View details for Web of Science ID 000557444000001
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Creating locally interacting Hamiltonians in the synthetic frequency dimension for photons
PHOTONICS RESEARCH
2020; 8 (9): B8–B14
View details for DOI 10.1364/PRJ.396731
View details for Web of Science ID 000565856300004
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Experimental demonstration of silicon photonic devices optimized by a flexible and deterministic pixel-by-pixel technique
APPLIED PHYSICS LETTERS
2020; 117 (7)
View details for DOI 10.1063/5.0013558
View details for Web of Science ID 000564165800001
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Maximal nighttime electrical power generation via optimal radiative cooling
OPTICS EXPRESS
2020; 28 (17): 25460–70
Abstract
We present a systematic optimization of nighttime thermoelectric power generation system utilizing radiative cooling. We show that an electrical power density >2 W/m2, two orders of magnitude higher than the previously reported experimental result, is achievable using existing technologies. This system combines radiative cooling and thermoelectric power generation and operates at night when solar energy harvesting is unavailable. The thermoelectric power generator (TEG) itself covers less than 1 percent of the system footprint area when achieving this optimal power generation, showing economic feasibility. We study the influence of emissivity spectra, thermal convection, thermoelectric figure of merit and the area ratio between the TEG and the radiative cooler on the power generation performance. We optimize the thermal radiation emitter attached to the cold side and propose practical material implementation. The importance of the optimal emitter is elucidated by the gain of 153% in power density compared to regular blackbody emitters.
View details for DOI 10.1364/OE.397714
View details for Web of Science ID 000560936200091
View details for PubMedID 32907066
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Design Principles of Apodized Grating Couplers
JOURNAL OF LIGHTWAVE TECHNOLOGY
2020; 38 (16): 4435–46
View details for DOI 10.1109/JLT.2020.2992574
View details for Web of Science ID 000554904400027
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Theoretical constraints on reciprocal and non-reciprocal many-body radiative heat transfer
PHYSICAL REVIEW B
2020; 102 (8)
View details for DOI 10.1103/PhysRevB.102.085401
View details for Web of Science ID 000554826100011
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Single-Photon Transport in a Topological Waveguide from a Dynamically Modulated Photonic System
PHYSICAL REVIEW APPLIED
2020; 14 (1)
View details for DOI 10.1103/PhysRevApplied.14.014063
View details for Web of Science ID 000551417100004
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PT-Symmetric Topological Edge-Gain Effect.
Physical review letters
2020; 125 (3): 033603
Abstract
We demonstrate a non-Hermitian topological effect that is characterized by having complex eigenvalues only in the edge states of a topological material, despite the fact that the material is completely uniform. Such an effect can be constructed in any topological structure formed by two gapped subsystems, e.g., a quantum spin-Hall system, with a suitable non-Hermitian coupling between the spins. The resulting complex-eigenvalued edge state is robust against defects due to the topological protection. In photonics, such an effect can be used for the implementation of topological lasers, in which a uniform pumping provides gain only in the edge lasing state. Furthermore, such a topological lasing model is reciprocal and is thus compatible with standard photonic platforms.
View details for DOI 10.1103/PhysRevLett.125.033603
View details for PubMedID 32745404
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Two-level quantum system as a macroscopic scatterer for ultraconfined two-dimensional photonic modes
PHYSICAL REVIEW A
2020; 102 (1)
View details for DOI 10.1103/PhysRevA.102.013717
View details for Web of Science ID 000549854700008
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Inverse Design of Photonic Crystals through Automatic Differentiation
ACS PHOTONICS
2020; 7 (7): 1729–41
View details for DOI 10.1021/acsphotonics.0c00327
View details for Web of Science ID 000551497000020
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PT-Symmetric Topological Edge-Gain Effect
PHYSICAL REVIEW LETTERS
2020; 125 (3)
View details for DOI 10.1103/PhysRevLett.125.033603
View details for Web of Science ID 000548060700007
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Bounds for Scattering from Absorptionless Electromagnetic Structures
PHYSICAL REVIEW APPLIED
2020; 14 (1)
View details for DOI 10.1103/PhysRevApplied.14.014025
View details for Web of Science ID 000615674000003
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Nonreciprocal Metamaterial Obeying Time-Reversal Symmetry.
Physical review letters
2020; 124 (25): 257403
Abstract
We introduce a class of non-Hermitian systems that break electromagnetic reciprocity while preserving time-reversal symmetry, and describe its novel polarization dynamics. We show that this class of systems can be realized using van der Waals heterostructures involving transition-metal dichalcogenides (TMDs). Our work provides a path towards achieving strong optical nonreciprocity and polarization-dependent directional amplification using compact, large-area and magnet-free structures.
View details for DOI 10.1103/PhysRevLett.124.257403
View details for PubMedID 32639792
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Nonreciprocal Metamaterial Obeying Time-Reversal Symmetry
PHYSICAL REVIEW LETTERS
2020; 124 (25)
View details for DOI 10.1103/PhysRevLett.124.257403
View details for Web of Science ID 000542522800010
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Alice strings in non-Hermitian systems
PHYSICAL REVIEW RESEARCH
2020; 2 (2)
View details for DOI 10.1103/PhysRevResearch.2.023226
View details for Web of Science ID 000603589200005
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Sub-Wavelength Passive Optical Isolators Using Photonic Structures Based on Weyl Semimetals
ADVANCED OPTICAL MATERIALS
2020
View details for DOI 10.1002/adom.202000100
View details for Web of Science ID 000535053400001
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Controlling the dopant profile for SRH suppression at low current densities in lambda approximate to 1330nm GaInAsP light-emitting diodes
APPLIED PHYSICS LETTERS
2020; 116 (20)
View details for DOI 10.1063/5.0002058
View details for Web of Science ID 000537237300001
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Homotopy characterization of non-Hermitian Hamiltonians
PHYSICAL REVIEW B
2020; 101 (20)
View details for DOI 10.1103/PhysRevB.101.205417
View details for Web of Science ID 000533157300006
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Retarded Charge-Carrier Recombination in Photoelectrochemical Cells from Plasmon-Induced Resonance Energy Transfer
ADVANCED ENERGY MATERIALS
2020
View details for DOI 10.1002/aenm.202000570
View details for Web of Science ID 000527995600001
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Robust and efficient wireless power transfer using a switch-mode implementation of a nonlinear parity-time symmetric circuit
NATURE ELECTRONICS
2020
View details for DOI 10.1038/s41928-020-0399-7
View details for Web of Science ID 000527902300001
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Experimental realization of arbitrary activation functions for optical neural networks
OPTICS EXPRESS
2020; 28 (8): 12138–48
View details for DOI 10.1364/OE.391473
View details for Web of Science ID 000526518300118
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Non-reciprocal polarization rotation using dynamic refractive index modulation
OPTICS EXPRESS
2020; 28 (8): 11974–82
View details for DOI 10.1364/OE.389357
View details for Web of Science ID 000526518300103
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Inverse-designed non-reciprocal pulse router for chip-based LiDAR
NATURE PHOTONICS
2020
View details for DOI 10.1038/s41566-020-0606-0
View details for Web of Science ID 000521525600003
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Meron Spin Textures in Momentum Space.
Physical review letters
2020; 124 (10): 106103
Abstract
We show that a momentum-space meron spin texture for electromagnetic fields in free space can be generated by controlling the interaction of light with a photonic crystal slab having a nonzero Berry curvature. These spin textures in momentum space have not been previously noted either in electronic or photonic systems. Breaking the inversion symmetry of a honeycomb photonic crystal gaps out the Dirac cones at the corners of Brillouin zone. The pseudospin textures of photonic bands near the gaps exhibit a meron or antimeron. Unlike the electronic systems, the pseudospin texture of the photonic modes manifests directly in the spin (polarization) texture of the leakage radiation, as the Dirac points can be above the light line. Such a spin texture provides a direct approach to visualize the local Berry curvature. Our work highlights the significant opportunities of using photonic structures for the exploration of topological spin textures, with potential applications towards topologically robust ways to manipulate polarizations and other modal characteristics of light.
View details for DOI 10.1103/PhysRevLett.124.106103
View details for PubMedID 32216415
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Meron Spin Textures in Momentum Space
PHYSICAL REVIEW LETTERS
2020; 124 (10)
View details for DOI 10.1103/PhysRevLett.124.106103
View details for Web of Science ID 000518820000020
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Fundamental Limits of the Dew-Harvesting Technology
NANOSCALE AND MICROSCALE THERMOPHYSICAL ENGINEERING
2020
View details for DOI 10.1080/15567265.2020.1722300
View details for Web of Science ID 000513375000001
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Nonreciprocal radiative heat transfer between two planar bodies
PHYSICAL REVIEW B
2020; 101 (8)
View details for DOI 10.1103/PhysRevB.101.085407
View details for Web of Science ID 000512773100005
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Compact Incoherent Image Differentiation with Nanophotonic Structures
ACS PHOTONICS
2020; 7 (2): 338–43
View details for DOI 10.1021/acsphotonics.9b01465
View details for Web of Science ID 000515214200004
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Determining the optimal learning rate in gradient-based electromagnetic optimization using the Shanks transformation in the Lippmann-Schwinger formalism
OPTICS LETTERS
2020; 45 (3): 595–98
Abstract
In gradient-based optimization of photonic devices, within the overall design parameter space, one iteratively performs a line search in a one-dimensional subspace as spanned by the search direction. While the search direction can be efficiently determined with the adjoint variable method, there has not been an efficient algorithm that determines the optimal learning rate that controls the distance one moves along the search direction. Here we introduce an efficient algorithm of determining the optimal learning rate, using the Shanks transformation in the Lippmann-Schwinger formalism. Our approach can determine very accurately the optimal learning rates at each epoch, with only a modest increase of computational cost. We show that this approach can significantly improve the figure of merits of the final structure, as compared to conventional methods for estimating the learning rate.
View details for DOI 10.1364/OL.379375
View details for Web of Science ID 000510869500001
View details for PubMedID 32004260
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Design of a multi-channel photonic crystal dielectric laser accelerator
IEEE. 2020
View details for Web of Science ID 000612090003182
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Efficient and Robust Wireless Power Transfer based on Parity-Time Symmetry
AMER INST PHYSICS. 2020
View details for DOI 10.1063/5.0031691
View details for Web of Science ID 000656159400007
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Higher-order topological insulators in synthetic dimensions.
Light, science & applications
2020; 9 (1): 131
Abstract
Conventional topological insulators support boundary states with dimension one lower than that of the bulk system that hosts them, and these states are topologically protected due to quantized bulk dipole moments. Recently, higher-order topological insulators have been proposed as a way of realizing topological states with dimensions two or more lower than that of the bulk due to the quantization of bulk quadrupole or octupole moments. However, all these proposals as well as experimental realizations have been restricted to real-space dimensions. Here, we construct photonic higher-order topological insulators (PHOTIs) in synthetic dimensions. We show the emergence of a quadrupole PHOTI supporting topologically protected corner modes in an array of modulated photonic molecules with a synthetic frequency dimension, where each photonic molecule comprises two coupled rings. By changing the phase difference of the modulation between adjacent coupled photonic molecules, we predict a dynamical topological phase transition in the PHOTI. Furthermore, we show that the concept of synthetic dimensions can be exploited to realize even higher-order multipole moments such as a fourth-order hexadecapole (16-pole) insulator supporting 0D corner modes in a 4D hypercubic synthetic lattice that cannot be realized in real-space lattices.
View details for DOI 10.1038/s41377-020-0334-8
View details for PubMedID 34282115
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Thermodynamic limits for simultaneous energy harvesting from the hot sun and cold outer space.
Light, science & applications
2020; 9 (1): 68
Abstract
The sun and outer space are two of the most important fundamental thermodynamic resources for renewable energy harvesting. A significant amount of work has focused on understanding the fundamental limit of energy harvesting from the sun. More recently, there have been several theoretical analyses of the fundamental limit of energy harvesting from outer space. However, far less is understood about the fundamental limits of simultaneous energy harvesting from both the sun and outer space. Here, we consider and introduce various schemes that are capable of simultaneous energy harvesting and elucidate the fundamental thermodynamic limits of these schemes. We show that the theoretical limits can far exceed the previously established limit associated with utilizing only one thermodynamic resource. Our results highlight the significant potential of simultaneous energy harvesting and indicate new fundamental opportunities for improving the efficiency of energy harvesting systems.
View details for DOI 10.1038/s41377-020-0296-x
View details for PubMedID 33893271
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Integrated near-field thermo-photovoltaics for heat recycling.
Nature communications
2020; 11 (1): 2545
Abstract
Energy transferred via thermal radiation between two surfaces separated by nanometer distances can be much larger than the blackbody limit. However, realizing a scalable platform that utilizes this near-field energy exchange mechanism to generate electricity remains a challenge. Here, we present a fully integrated, reconfigurable and scalable platform operating in the near-field regime that performs controlled heat extraction and energy recycling. Our platform relies on an integrated nano-electromechanical system that enables precise positioning of a thermal emitter within nanometer distances from a room-temperature germanium photodetector to form a thermo-photovoltaic cell. We demonstrate over an order of magnitude enhancement of power generation (Pgen ~ 1.25 μWcm-2) in our thermo-photovoltaic cell by actively tuning the gap between a hot-emitter (TE ~ 880 K) and the cold photodetector (TD ~ 300 K) from ~ 500 nm down to ~ 100 nm. Our nano-electromechanical system consumes negligible tuning power (Pgen/PNEMS ~ 104) and relies on scalable silicon-based process technologies.
View details for DOI 10.1038/s41467-020-16197-6
View details for PubMedID 32439917
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Axion-Field-Enabled Nonreciprocal Thermal Radiation in Weyl Semimetals.
Nano letters
2020
Abstract
Objects around us constantly emit and absorb thermal radiation. The emission and absorption processes are governed by two fundamental radiative properties: emissivity and absorptivity. For reciprocal systems, the emissivity and absorptivity are restricted to be equal by Kirchhoff's law of thermal radiation. This restriction limits the degree of freedom to control thermal radiation and contributes to an intrinsic loss mechanism in photonic energy harvesting systems. Existing approaches to violate Kirchhoff's law typically utilize magneto-optical effects with an external magnetic field. However, these approaches require either a strong magnetic field (∼3T) or narrow-band resonances under a moderate magnetic field (∼0.3T), because the nonreciprocity in conventional magneto-optical effects is weak in the thermal wavelength range. Here, we show that the axion electrodynamics in magnetic Weyl semimetals can be used to construct strongly nonreciprocal thermal emitters that nearly completely violate Kirchhoff's law over broad angular and frequency ranges without requiring any external magnetic field.
View details for DOI 10.1021/acs.nanolett.9b05179
View details for PubMedID 32073859
-
Thermodynamic limits for simultaneous energy harvesting from the hot sun and cold outer space.
Light, science & applications
2020; 9: 68
Abstract
The sun and outer space are two of the most important fundamental thermodynamic resources for renewable energy harvesting. A significant amount of work has focused on understanding the fundamental limit of energy harvesting from the sun. More recently, there have been several theoretical analyses of the fundamental limit of energy harvesting from outer space. However, far less is understood about the fundamental limits of simultaneous energy harvesting from both the sun and outer space. Here, we consider and introduce various schemes that are capable of simultaneous energy harvesting and elucidate the fundamental thermodynamic limits of these schemes. We show that the theoretical limits can far exceed the previously established limit associated with utilizing only one thermodynamic resource. Our results highlight the significant potential of simultaneous energy harvesting and indicate new fundamental opportunities for improving the efficiency of energy harvesting systems.
View details for DOI 10.1038/s41377-020-0296-x
View details for PubMedID 32351692
View details for PubMedCentralID PMC7181797
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Universal programmable photonic architecture for quantum information processing
Physical Review A
2020; 101 (4): 042319
View details for DOI 10.1103/PhysRevA.101.042319
-
Efficient second harmonic generation in a doubly resonant photonic crystal cavity based on a bound state in the continuum
IEEE. 2020
View details for Web of Science ID 000612237500115
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Terrestrial radiative cooling: Using the cold universe as a renewable and sustainable energy source.
Science (New York, N.Y.)
2020; 370 (6518): 786–91
Abstract
Photonic materials designed at wavelength scales have enabled a range of emerging energy technologies, from solid-state lighting to efficient photovoltaics that have transformed global energy landscapes. Daytime passive radiative cooling materials shed heat from the ground to the cold universe by taking advantage of the terrestrial thermal radiation that is as large as the renewable solar energy. Newly developed photonic materials permit subambient cooling under direct sunshine, and their applications are expanding rapidly enabled by scalable manufacturing. We review here the recent advancement of daytime subambient radiative cooling materials, which allow energy-efficient cooling and are paving the way toward technologies that harvest the coldness from the universe as a new renewable energy source.
View details for DOI 10.1126/science.abb0971
View details for PubMedID 33184205
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Experimental demonstration of acoustic semimetal with topologically charged nodal surface.
Science advances
2020; 6 (8): eaav2360
Abstract
Weyl points are zero-dimensional band degeneracy in three-dimensional momentum space that has nonzero topological charges. The presence of the topological charges protects the degeneracy points against perturbations and enables a variety of fascinating phenomena. It is so far unclear whether such charged objects can occur in higher dimensions. Here, we introduce the concept of charged nodal surface, a two-dimensional band degeneracy surface in momentum space that is topologically charged. We provide an effective Hamiltonian for this charged nodal surface and show that such a Hamiltonian can be implemented in a tight-binding model. This is followed by an experimental realization in a phononic crystal. The measured topologically protected surface arc state of such an acoustic semimetal reproduces excellently the full-wave simulations. Creating high-dimensional charged geometric objects in momentum space promises a broad range of unexplored topological physics.
View details for DOI 10.1126/sciadv.aav2360
View details for PubMedID 32128388
View details for PubMedCentralID PMC7034989
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Photonic Refrigeration from Time-Modulated Thermal Emission.
Physical review letters
2020; 124 (7): 077402
Abstract
We develop theoretical and computational formalisms to describe thermal radiation from temporally modulated systems. We show that such a modulation results in a photon-based active cooling mechanism. This mechanism has a high thermodynamic performance that can approach the Carnot limit. Our work points to exciting new avenues in active, time-modulated control of thermal emission for cooling and energy harvesting applications.
View details for DOI 10.1103/PhysRevLett.124.077402
View details for PubMedID 32142345
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Broadening Near-Field Emission for Performance Enhancement in Thermophotovoltaics.
Nano letters
2020
Abstract
The conventional notion for achieving high efficiency in thermophotovoltaics (TPVs) is to use a monochromatic emission at a photon energy corresponding to the band gap of the cell. Here, we prove theoretically that such a notion is only accurate under idealized conditions and further show that, when nonradiative recombination is taken into account, efficiency improvement can be achieved by broadening the emission spectrum, due to an enhancement in the open-circuit voltage. Broadening the emission spectrum also improves the electrical power density, by increasing the short-circuit current. Hence, broadening the emission spectrum can simultaneously improve the efficiency and power density of practical TPV systems. To illustrate these findings, we focus on surface polariton-mediated near-field TPVs. We propose a versatile design strategy for broadening the emission spectrum via stacking of multiple plasmonic thin film layers. As an example, we consider a realistic ITO/InAs TPV and predict a conversion efficiency of 50% simultaneously with a power density of nearly 80 W/cm2 at a 1300 K emitter temperature. The performance of our proposed system far exceeds previous works in similar systems using a single plasmonic layer emitter.
View details for DOI 10.1021/acs.nanolett.9b04762
View details for PubMedID 31978305
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Photonic Quantum Programmable Gate Arrays
IEEE. 2020
View details for Web of Science ID 000612090002170
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Nonreciprocal radiative heat transfer between two planar bodies
IEEE. 2020
View details for Web of Science ID 000612090002227
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Dynamics for encircling an exceptional point in a nonlinear non-Hermitian system
IEEE. 2020
View details for Web of Science ID 000612090002171
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Active photonic cooling using time-modulated thermal emission
IEEE. 2020
View details for Web of Science ID 000612090000076
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Tunable Nonlinear Activation Functions for Optical Neural Networks
IEEE. 2020
View details for Web of Science ID 000612090000353
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Inverse-designed optical interconnect based on multimode photonics and mode-division multiplexing
IEEE. 2020
View details for Web of Science ID 000612090002022
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Broadband Linear-to-Circular Polarization Conversion Enabled by Birefringent Reflective Metasurfaces
IEEE. 2020
View details for Web of Science ID 000612090003198
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PT -symmetric topological edge-gain effect
IEEE. 2020
View details for Web of Science ID 000612090003124
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Penetration Depth Engineering in Plasmonic Metafilms for Enhanced Reflection and Confinement
IEEE. 2020
View details for Web of Science ID 000612090000453
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Higher-order topological insulators in synthetic dimensions.
Light, science & applications
2020; 9: 131
Abstract
Conventional topological insulators support boundary states with dimension one lower than that of the bulk system that hosts them, and these states are topologically protected due to quantized bulk dipole moments. Recently, higher-order topological insulators have been proposed as a way of realizing topological states with dimensions two or more lower than that of the bulk due to the quantization of bulk quadrupole or octupole moments. However, all these proposals as well as experimental realizations have been restricted to real-space dimensions. Here, we construct photonic higher-order topological insulators (PHOTIs) in synthetic dimensions. We show the emergence of a quadrupole PHOTI supporting topologically protected corner modes in an array of modulated photonic molecules with a synthetic frequency dimension, where each photonic molecule comprises two coupled rings. By changing the phase difference of the modulation between adjacent coupled photonic molecules, we predict a dynamical topological phase transition in the PHOTI. Furthermore, we show that the concept of synthetic dimensions can be exploited to realize even higher-order multipole moments such as a fourth-order hexadecapole (16-pole) insulator supporting 0D corner modes in a 4D hypercubic synthetic lattice that cannot be realized in real-space lattices.
View details for DOI 10.1038/s41377-020-0334-8
View details for PubMedID 32704364
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Reprogrammable Electro-Optic Nonlinear Activation Functions for Optical Neural Networks
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2020; 26 (1)
View details for DOI 10.1109/JSTQE.2019.2930455
View details for Web of Science ID 000480342600001
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Absence of unidirectionally propagating surface plasmon-polaritons at nonreciprocal metal-dielectric interfaces.
Nature communications
2020; 11 (1): 674
Abstract
In the presence of an external magnetic field, the surface plasmon polariton that exists at the metal-dielectric interface is believed to support a unidirectional frequency range near the surface plasmon frequency, where the surface plasmon polariton propagates along one but not the opposite direction. Recent works have pointed to some of the paradoxical consequences of such a unidirectional range, including in particular the violation of the time-bandwidth product constraint that should otherwise apply in general in static systems. Here we show that such a unidirectional frequency range is nonphysical using both a general thermodynamic argument and a detailed calculation based on a nonlocal hydrodynamic Drude model for the metal permittivity. Our calculation reveals that the surface plasmon-polariton at metal-dielectric interfaces remains bidirectional for all frequencies.
View details for DOI 10.1038/s41467-020-14504-9
View details for PubMedID 32015328
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Doubly resonant photonic crystal cavity based on a bound state in the continuum for efficient second harmonic generation
IEEE. 2020
View details for Web of Science ID 000612090001498
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Topological Behaviors in Networks of Time-Multiplexed Optical Resonators
IEEE. 2020
View details for Web of Science ID 000612090003101
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Recurrent Machine Learning and Computing with Nonlinear Optical Waves
IEEE. 2020
View details for Web of Science ID 000612090001433
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Silicon nitride waveguide as a power delivery component for dielectric laser accelerators
IEEE. 2020
View details for Web of Science ID 000612090002213
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Parallel Fault-Tolerant Programming and Optimization of Photonic Neural Networks
IEEE. 2020
View details for Web of Science ID 000612090001197
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Broadband Linear-to-Circular Polarization Conversion Enabled by Birefringent Off-Resonance Reflective Metasurfaces.
Physical review letters
2019; 123 (23): 237401
Abstract
Due to the scarcity of circular polarization light sources, linear-to-circular polarization conversion is required to generate circularly polarized light for a variety of applications. Despite significant past efforts, broadband linear-to-circular polarization conversion remains elusive particularly in the terahertz and midinfrared frequency ranges. Here we propose a novel mechanism based on coupled mode theory, and experimentally demonstrate at terahertz frequencies that highly efficient (power conversion efficiency approaching unity) and ultrabroadband (fractional bandwidth up to 80%) linear-to-circular polarization conversion can be accomplished by the judicious design of birefringent metasurfaces. The underlying mechanism operates in the frequency range between well separated resonances, and relies upon the phase response of these resonances away from the resonant frequencies, as well as the balance of the resonant and nonresonant channels. This mechanism is applicable for any operating frequencies from microwave to visible. The present Letter potentially opens a wide range of opportunities in wireless communications, spectroscopy, and emergent quantum materials research where circularly polarized light is desired.
View details for DOI 10.1103/PhysRevLett.123.237401
View details for PubMedID 31868454
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Broadband Linear-to-Circular Polarization Conversion Enabled by Birefringent Off-Resonance Reflective Metasurfaces
PHYSICAL REVIEW LETTERS
2019; 122 (23)
View details for DOI 10.1103/PhysRevLett.123.237401
View details for Web of Science ID 000500743400021
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Wave physics as an analog recurrent neural network.
Science advances
2019; 5 (12): eaay6946
Abstract
Analog machine learning hardware platforms promise to be faster and more energy efficient than their digital counterparts. Wave physics, as found in acoustics and optics, is a natural candidate for building analog processors for time-varying signals. Here, we identify a mapping between the dynamics of wave physics and the computation in recurrent neural networks. This mapping indicates that physical wave systems can be trained to learn complex features in temporal data, using standard training techniques for neural networks. As a demonstration, we show that an inverse-designed inhomogeneous medium can perform vowel classification on raw audio signals as their waveforms scatter and propagate through it, achieving performance comparable to a standard digital implementation of a recurrent neural network. These findings pave the way for a new class of analog machine learning platforms, capable of fast and efficient processing of information in its native domain.
View details for DOI 10.1126/sciadv.aay6946
View details for PubMedID 31903420
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Ultrafast pyroelectric photodetection with on-chip spectral filters.
Nature materials
2019
Abstract
Thermal detectors, such as bolometric, pyroelectric and thermoelectric devices, are uniquely capable of sensing incident radiation for any electromagnetic frequency; however, the response times of practical devices are typically on the millisecond scale1-7. By integrating a plasmonic metasurface with an aluminium nitride pyroelectric thin film, we demonstrate spectrally selective, room-temperature pyroelectric detectors from 660-2,000nm with an instrument-limited 1.7ns full width at half maximum and 700ps rise time. Heat generated from light absorption diffuses through the subwavelength absorber into the pyroelectric film producing responsivities up to 0.18VW-1 due to the temperature-dependent spontaneous polarization of the pyroelectric films. Moreover, finite-element simulations reveal the possibility of reaching a 25ps full width at half maximum and 6ps rise time rivalling that of semiconductor photodiodes8. This design approach has the potential to realize large-area, inexpensive gigahertz pyroelectric detectors for wavelength-specific detection from the ultraviolet to short-wave infrared or beyond for, for example, high-speed hyperspectral imaging.
View details for DOI 10.1038/s41563-019-0538-6
View details for PubMedID 31768011
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Generating Light from Darkness
JOULE
2019; 3 (11): 2679–86
View details for DOI 10.1016/j.joule.2019.08.009
View details for Web of Science ID 000497987900012
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Relation between photon thermal Hall effect and persistent heat current in nonreciprocal radiative heat transfer
PHYSICAL REVIEW B
2019; 100 (20)
View details for DOI 10.1103/PhysRevB.100.205416
View details for Web of Science ID 000496925100006
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Rare Earth Doped Optical Fibers with Multi-section Core.
iScience
2019; 22: 423–29
Abstract
The gain bandwidth of a single-mode fiber is limited by the atomic transitions of one rare earth gain element. Here we overcome this long-standing challenge by designing a new single-mode fiber with multi-section core, where each section is doped with different gain element. We theoretically propose and experimentally demonstrate that this configuration provides a gain bandwidth well beyond the capability of conventional design, whereas the inclusion of multiple sections does not compromise single-mode operation or the quality of the transverse modal profile. This new fiber will be beneficial in realizing all fiber laser systems with few-cycle pulse duration or octave tunability.
View details for DOI 10.1016/j.isci.2019.11.017
View details for PubMedID 31816529
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Casimir force between two plasmonic metallic plates from a real frequency perspective
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2019; 36 (11): 2981–88
View details for DOI 10.1364/JOSAB.36.002981
View details for Web of Science ID 000493941200007
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Forward-Mode Differentiation of Maxwell's Equations
ACS PHOTONICS
2019; 6 (11): 3010–16
View details for DOI 10.1021/acsphotonics.9b01238
View details for Web of Science ID 000499742000049
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Nighttime radiative cooling in hot and humid climates
OPTICS EXPRESS
2019; 27 (22): 31587–98
Abstract
Most existing experiments on radiative cooling are conducted in dry climates for better performance. However, many important applications require cooling in hot and humid climates. Here we theoretically analyze the temperature reduction and cooling flux at nighttime with the ambient temperature (Tambient) ranging from 0-40 ∘C and the relative humidity (RH) from 0-100%. Our analysis reveals an interesting crossover: for lower (higher) RH, higher (lower) Tambient results in better cooling. Experimentally, we show that radiative cooling of 5 ∘C below ambient can be achieved even at Tambient = 29 ∘C with RH = 100%.
View details for DOI 10.1364/OE.27.031587
View details for Web of Science ID 000492996000041
View details for PubMedID 31684390
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Efficient pixel-by-pixel optimization of photonic devices utilizing the Dyson's equation in a Green's function formalism: Part II. Implementation using standard electromagnetic solvers
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2019; 36 (9): 2387–94
View details for DOI 10.1364/JOSAB.36.002387
View details for Web of Science ID 000483999400005
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Near-complete violation of Kirchhoff's law of thermal radiation with a 0.3 T magnetic field
OPTICS LETTERS
2019; 44 (17): 4203–6
Abstract
The capability to overcome Kirchhoff's law of thermal radiation provides new opportunities in energy harvesting and thermal radiation control. Previously, design towards demonstrating such capability requires a magnetic field of 3 T, which is difficult to achieve in practice. In this work, we propose a nanophotonic design that can achieve such capability with a far more modest magnetic field of 0.3 Tesla, a level that can be achieved with permanent magnets. Our design uses guided resonance in low-loss dielectric gratings sitting on a magneto-optical material, which provides significant enhancement on the sensitivity to the external magnetic field.
View details for DOI 10.1364/OL.44.004203
View details for Web of Science ID 000483918900029
View details for PubMedID 31465363
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Efficient pixel-by-pixel optimization of photonic devices utilizing the Dyson's equation in a Green's function formalism: Part I. Implementation with the method of discrete dipole approximation
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2019; 36 (9): 2378–86
View details for DOI 10.1364/JOSAB.36.002378
View details for Web of Science ID 000483999400004
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Wave optics light-trapping theory: mathematical justification and ultimate limit on enhancement
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2019; 36 (9): 2414–22
View details for DOI 10.1364/JOSAB.36.002414
View details for Web of Science ID 000483999400009
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Doubly resonant chi((2)) nonlinear photonic crystal cavity based on a bound state in the continuum
OPTICA
2019; 6 (8): 1039–45
View details for DOI 10.1364/OPTICA.6.001039
View details for Web of Science ID 000482136700016
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High-Temperature Polarization-Free III-Nitride Solar Cells with Self-Cooling Effects
ACS PHOTONICS
2019; 6 (8): 2096–2103
View details for DOI 10.1021/acsphotonics.9b00655
View details for Web of Science ID 000482545400036
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Penetration Depth Reduction with Plasmonic Metafilms
ACS PHOTONICS
2019; 6 (8): 2049–55
View details for DOI 10.1021/acsphotonics.9b00493
View details for Web of Science ID 000482545400030
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Accelerating adjoint variable method based photonic optimization with Schur complement domain decomposition
OPTICS EXPRESS
2019; 27 (15): 20711–19
View details for DOI 10.1364/OE.27.020711
View details for Web of Science ID 000476652500051
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Experimental band structure spectroscopy along a synthetic dimension.
Nature communications
2019; 10 (1): 3122
Abstract
There has been significant recent interest in synthetic dimensions, where internal degrees of freedom of a particle are coupled to form higher-dimensional lattices in lower-dimensional physical structures. For these systems, the concept of band structure along the synthetic dimension plays a central role in their theoretical description. Here we provide a direct experimental measurement of the band structure along the synthetic dimension. By dynamically modulating a resonator at frequencies commensurate with its mode spacing, we create a periodically driven lattice of coupled modes in the frequency dimension. The strength and range of couplings can be dynamically reconfigured by changing the modulation amplitude and frequency. We show theoretically and demonstrate experimentally that time-resolved transmission measurements of this system provide a direct readout of its band structure. We also realize long-range coupling, gauge potentials and nonreciprocal bands by simply incorporating additional frequency drives, enabling great flexibility in band structure engineering.
View details for DOI 10.1038/s41467-019-11117-9
View details for PubMedID 31311928
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Arbitrary Polarization Conversion with a Photonic Crystal Slab
ADVANCED OPTICAL MATERIALS
2019; 7 (14)
View details for DOI 10.1002/adom.201801453
View details for Web of Science ID 000476680600011
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Photon Blockade in Weakly Driven Cavity Quantum Electrodynamics Systems with Many Emitters.
Physical review letters
2019; 122 (24): 243602
Abstract
We use the scattering matrix formalism to analyze photon blockade in coherently driven cavity quantum electrodynamics systems with a weak drive. By approximating the weak coherent drive by an input single- and two-photon Fock state, we reduce the computational complexity of the transmission and the two-photon correlation function from exponential to polynomial in the number of emitters. This enables us to easily analyze cavity-based systems containing ∼50 quantum emitters with modest computational resources. Using this approach we study the coherence statistics of photon blockade while increasing the number of emitters for resonant and detuned multiemitter cavity quantum electrodynamics systems-we find that increasing the number of emitters worsens photon blockade in resonant systems, and improves it in detuned systems. We also analyze the impact of inhomogeneous broadening in the emitter frequencies on the photon blockade through this system.
View details for DOI 10.1103/PhysRevLett.122.243602
View details for PubMedID 31322381
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Temperature Regulation in Colored Infrared-Transparent Polyethylene Textiles
JOULE
2019; 3 (6): 1478–86
View details for DOI 10.1016/j.joule.2019.03.015
View details for Web of Science ID 000472067900014
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Reconfigurable Photonic Circuit for Controlled Power Delivery to Laser-Driven Accelerators on a Chip
PHYSICAL REVIEW APPLIED
2019; 11 (6)
View details for DOI 10.1103/PhysRevApplied.11.064014
View details for Web of Science ID 000470894800003
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Implications of exceptional points for few-photon transport in waveguide quantum electrodynamics
PHYSICAL REVIEW A
2019; 99 (6)
View details for DOI 10.1103/PhysRevA.99.063806
View details for Web of Science ID 000470818300003
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Self-sustaining thermophotonic circuits.
Proceedings of the National Academy of Sciences of the United States of America
2019
Abstract
Photons represent one of the most important heat carriers. The ability to convert photon heat flow to electricity is therefore of substantial importance for renewable energy applications. However, photon-based systems that convert heat to electricity, including thermophotovoltaic systems where photons are generated from passive thermal emitters, have long been limited by low power density. This limitation persists even with near-field enhancement techniques. Thermophotonic systems, which utilize active photon emitters such as light-emitting diodes, have the potential to significantly further enhance the power density. However, this potential has not been realized in practice, due in part to the fundamental difficulty in thermodynamics of designing a self-sustaining circuit that enables steady-state power generation. Here, we overcome such difficulty by introducing a configuration where the light-emitting diodes are connected in series, and thus multiple photons can be generated from a single injected electron. As a result we propose a self-sustaining thermophotonic circuit where the steady-state power density can exceed thermophotovoltaic systems by many orders of magnitude. This work points to possibilities for constructing heat engines with light as the working medium. The flexibility of controlling the relations between electron and photon flux, as we show in our design, may also be of general importance for optoelectronics-based energy technology.
View details for DOI 10.1073/pnas.1904938116
View details for PubMedID 31118287
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Broadband Optical Switch based on an Achromatic Photonic Gauge Potential in Dynamically Modulated Waveguides
PHYSICAL REVIEW APPLIED
2019; 11 (5)
View details for DOI 10.1103/PhysRevApplied.11.054035
View details for Web of Science ID 000467743700003
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Compact dynamic optical isolator based on tandem phase modulators
OPTICS LETTERS
2019; 44 (9): 2240–43
Abstract
Non-magnetic dynamic optical isolators, constructed from modulators, provide a complementary metal oxide semiconductor (CMOS)-compatible approach to optical isolation in integrated photonics. The size of these isolators is strongly constrained by both the frequency and strength of optical modulation. Recent developments in modulators have indicated that large modulation strength, with a magnitude refractive index modulation up to unity, may be possible at gigahertz modulation frequency. In this Letter, we show that a previously proposed dynamic isolator design, based on tandem modulators, can be modified to take advantage of the possibility of such large modulation strength. Compared with the previously proposed tandem modulator design, our modification can lead to significant reduction of the device length without the need to increase modulation frequency.
View details for DOI 10.1364/OL.44.002240
View details for Web of Science ID 000466351300028
View details for PubMedID 31042193
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Experimental demonstration of energy harvesting from the sky using the negative illumination effect of a semiconductor photodiode
APPLIED PHYSICS LETTERS
2019; 114 (16)
View details for DOI 10.1063/1.5089783
View details for Web of Science ID 000466264600002
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Laterally confined photonic crystal surface emitting laser incorporating monolayer tungsten disulfide
NPJ 2D MATERIALS AND APPLICATIONS
2019; 3
View details for DOI 10.1038/s41699-019-0099-1
View details for Web of Science ID 000466144500001
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Anti-parity-time symmetry in diffusive systems
SCIENCE
2019; 364 (6436): 170-+
View details for DOI 10.1126/science.aaw6259
View details for Web of Science ID 000464620000040
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Connection of temporal coupled-mode-theory formalisms for a resonant optical system and its time-reversal conjugate
PHYSICAL REVIEW A
2019; 99 (3)
View details for DOI 10.1103/PhysRevA.99.033839
View details for Web of Science ID 000461898500007
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Photonic Gauge Potential in One Cavity with Synthetic Frequency and Orbital Angular Momentum Dimensions.
Physical review letters
2019; 122 (8): 083903
Abstract
We explore a single degenerate optical cavity supporting a synthetic two-dimensional space, which includes the frequency and the orbital angular momentum (OAM) axes of light. We create the effective gauge potential inside this synthetic space and show that the system exhibits topologically protected one-way edge states along the OAM axis at the boundaries of the frequency dimension. In this synthetic space, we present a robust generation and manipulation of entanglement between the frequency and OAM of photons. Our Letter shows that a higher-dimensional synthetic space involving multiple degrees of freedom of light can be achieved in a "zero-dimensional" spatial structure, pointing towards a unique platform to explore topological photonics and to realize potential applications in optical communications and quantum information processing.
View details for DOI 10.1103/PhysRevLett.122.083903
View details for PubMedID 30932579
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Gate-Tunable Near-Field Heat Transfer
ACS PHOTONICS
2019; 6 (3): 709–19
View details for DOI 10.1021/acsphotonics.8b01585
View details for Web of Science ID 000462260100018
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Scattering of electromagnetic waves by cylinder inside uniaxial hyperbolic medium
OPTICS EXPRESS
2019; 27 (4): 3991–4003
View details for DOI 10.1364/OE.27.003991
View details for Web of Science ID 000459152800033
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Modal approach to optical forces between waveguides as derived by transformation optics formalism
OPTICS LETTERS
2019; 44 (4): 867–70
Abstract
Optical force between two lossless waveguides has been described by two approaches. One approach is the explicit description of the force by the Maxwell stress tensor. Another approach is to describe the modal force in terms of the derivative of the eigenmode frequency with respect to the distance variation. Here, we analytically prove the equivalence of these two approaches for lossless waveguides having arbitrary cross sections through the use of transformation optics formalism. Our derivation is applicable to both pressure and shear forces. We also show that these two approaches are not equivalent in the presence of loss.
View details for DOI 10.1364/OL.44.000867
View details for Web of Science ID 000458786800037
View details for PubMedID 30768007
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Dynamics for encircling an exceptions point in a nonlinear non-Hermitian system
OPTICS LETTERS
2019; 44 (3): 638–41
Abstract
We study the dynamics near an exceptional point in a nonlinear non-Hermitian system consisting of a pair of resonators. One of the resonators has a linear loss, and the other resonator has a saturable gain. We show that the system dynamics exhibit chiral characteristics. And moreover, unique to the nonlinear system, such dynamics allow one to adiabatically switch between bistable states at the same system parameter. Such bistable switching is potentially interesting in optical memory based on coupled laser systems.
View details for DOI 10.1364/OL.44.000638
View details for Web of Science ID 000457292400044
View details for PubMedID 30702698
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High Reflection from a One-Dimensional Array of Graphene Nanoribbons
ACS PHOTONICS
2019; 6 (2): 339–44
View details for DOI 10.1021/acsphotonics.8b01640
View details for Web of Science ID 000459642800014
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Simultaneously and Synergistically Harvest Energy from the Sun and Outer Space
JOULE
2019; 3 (1): 101–10
View details for DOI 10.1016/j.joule.2018.10.009
View details for Web of Science ID 000457552800010
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Silicon nitride waveguide as a power delivery component for on-chip dielectric laser accelerators
OPTICS LETTERS
2019; 44 (2): 335–38
Abstract
We study the weakly guided silicon nitride waveguide as an on-chip power delivery solution for dielectric laser accelerators (DLAs). We focus on the two main limiting factors on the waveguide network for DLAs: the optical damage and nonlinear characteristics. The typical delivered fluence at the onset of optical damage is measured to be ∼0.19 J/cm2 at a 2 μm central wavelength and 250 fs pulse width. This damage fluence is lower than that of the bulk Si3N4 (∼0.65 J/cm2), but higher than that of bulk silicon (∼0.17 J/cm2). We also report the nonlinearity-induced spectrum and phase variance of the output pulse at this pulse duration. We find that a total waveguide length within 3 mm is sufficient to avoid significant self-phase modulation effects when operating slightly below the damage threshold. We also estimate that one SiNx waveguide can power 70 μm silicon dual pillar DLAs from a single side, based on the results from the recent free-space DLA experiment.
View details for DOI 10.1364/OL.44.000335
View details for Web of Science ID 000455620100039
View details for PubMedID 30644894
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Direction-dependent parity-time phase transition and nonreciprocal amplification with dynamic gain-loss modulation
PHYSICAL REVIEW A
2019; 99 (1)
View details for DOI 10.1103/PhysRevA.99.013824
View details for Web of Science ID 000455683900018
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Subwavelength angle-sensing photodetectors inspired by internally coupled ears in small animals
SPIE-INT SOC OPTICAL ENGINEERING. 2019
View details for DOI 10.1117/12.2529594
View details for Web of Science ID 000502134800007
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Optically pumped 1 mu m low threshold photonic crystal surface emitting lasers grown on GaAs substrate
IEEE. 2019
View details for Web of Science ID 000520481500155
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Training of Photonic Neural Networks through In Situ Backpropagation
IEEE. 2019
View details for Web of Science ID 000482226301171
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Adjoint-based inverse design of nonlinear nanophotonic devices
IEEE. 2019
View details for Web of Science ID 000482226302049
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Adjoint-based optimization of active nanophotonic devices
IEEE. 2019
View details for Web of Science ID 000482226301422
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Broadband Switches Using Photonic Aharonov-Bohm Interferometers and Dynamic Modulation
IEEE. 2019
View details for Web of Science ID 000482226301357
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Pulse shortening in two coupled rings under amplitude modulations with parity-time symmetry
IEEE. 2019
View details for Web of Science ID 000482226302433
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Optical computing of spatial differentiation without Fourier optics
IEEE. 2019
View details for Web of Science ID 000482226300144
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Scattering of electromagnetic waves by cylinder inside uniaxial hyperbolic medium
SPIE-INT SOC OPTICAL ENGINEERING. 2019
View details for DOI 10.1117/12.2527212
View details for Web of Science ID 000511108800014
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Optical Image Processing Using Photonic Crystal Slab
SPIE-INT SOC OPTICAL ENGINEERING. 2019
View details for DOI 10.1117/12.2516018
View details for Web of Science ID 000511111900007
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High Reflection from a One-Dimensional Array of Graphene Nanoribbons
IEEE. 2019
View details for Web of Science ID 000482226301492
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Absence of frequency ranges of undirectional propagation in nonreciprocal plasmonics
IEEE. 2019
View details for Web of Science ID 000482226302198
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Experimental Band Structure Spectroscopy along the Synthetic Dimension
IEEE. 2019
View details for Web of Science ID 000482226300311
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Lossless Zero-Index Guided Modes via Bound States in the Continuum
IEEE. 2019
View details for Web of Science ID 000482226302096
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Design of a tapered slot waveguide dielectric laser accelerator for sub-relativistic electrons
IEEE. 2019
View details for Web of Science ID 000482226300274
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Thermal meta-device in analogue of zero-index photonics
NATURE MATERIALS
2019; 18 (1): 48-+
View details for DOI 10.1038/s41563-018-0239-6
View details for Web of Science ID 000452876200015
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Fano resonance photonic crystal filters and modulators
PHOTONIC CRYSTAL METASURFACE OPTOELECTRONICS
2019; 100: 149–88
View details for DOI 10.1016/bs.semsem.2019.04.003
View details for Web of Science ID 000500339500007
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Direct Object Recognition Without Line-of-Sight Using Optical Coherence
IEEE. 2019: 11729–38
View details for DOI 10.1109/CVPR.2019.01201
View details for Web of Science ID 000542649305036
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A single photonic cavity with two independent physical synthetic dimensions.
Science (New York, N.Y.)
2019
Abstract
The concept of synthetic dimensions has generated interest in many branches of science ranging from ultracold-atomic physics to photonics, as it provides a versatile platform for realizing effective gauge potentials and topological physics. Previous experiments have augmented the real-space dimensionality by one additional physical synthetic dimension. We endow a single ring resonator with two independent physical synthetic dimensions. Our system consists of a temporally modulated ring resonator with spatial coupling between the clockwise and counterclockwise modes, creating a synthetic Hall ladder along the frequency and pseudospin degrees of freedom for photons propagating in the ring. We observe a wide variety of rich physics, including effective spin-orbit coupling, magnetic fields, spin-momentum locking, a Meissner-to-vortex phase transition, and signatures of topological chiral one-way edge currents, completely in synthetic dimensions. Our experiments demonstrate that higher-dimensional physics can be studied in simple systems by leveraging the concept of multiple simultaneous synthetic dimensions.
View details for DOI 10.1126/science.aaz3071
View details for PubMedID 31780626
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Fano resonance principles in photonic crystal slabs
PHOTONIC CRYSTAL METASURFACE OPTOELECTRONICS
2019; 100: 1–12
View details for DOI 10.1016/bs.semsem.2019.04.001
View details for Web of Science ID 000500339500002
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Optical image processing using photonic crystal slab
PHOTONIC CRYSTAL METASURFACE OPTOELECTRONICS
2019; 100: 93–114
View details for DOI 10.1016/bs.semsem.2019.02.001
View details for Web of Science ID 000500339500005
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Anti-parity-time symmetry in diffusive systems.
Science (New York, N.Y.)
2019; 364 (6436): 170–73
Abstract
Various concepts related to parity-time symmetry, including anti-parity-time symmetry, have found broad applications in wave physics. Wave systems are fundamentally described by Hermitian operators, whereas their unusual properties are introduced by incorporation of gain and loss. We propose that the related physics need not be restricted to wave dynamics, and we consider systems described by diffusive dynamics. We study the heat transfer in two countermoving media and show that this system exhibits anti-parity-time symmetry. The spontaneous symmetry breaking results in a phase transition from motionless temperature profiles, despite the mechanical motion of the background, to moving temperature profiles. Our results extend the concepts of parity-time symmetry beyond wave physics and may offer opportunities to manipulate heat and mass transport.
View details for PubMedID 30975886
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Electronically programmable photonic molecule
NATURE PHOTONICS
2019; 13 (1): 36-+
View details for DOI 10.1038/s41566-018-0317-y
View details for Web of Science ID 000453254900014
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Experimental Demonstration of Dynamical Input Isolation in Nonadiabatically Modulated Photonic Cavities
ACS PHOTONICS
2019; 6 (1): 162–69
View details for DOI 10.1021/acsphotonics.8b01310
View details for Web of Science ID 000456350400023
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Zero-Index Bound States in the Continuum.
Physical review letters
2018; 121 (26): 263901
Abstract
Metamaterials with an effective zero refractive index associated with their electromagnetic response are sought for a number of applications in communications and nonlinear optics. A promising way that this can be achieved in all-dielectric photonic crystals is through the design of a Dirac cone at zero Bloch wave vector in the photonic band structure. In the optical frequency range, the natural way to implement this design is through the use of a photonic crystal slab. In the existing implementation, however, the zero-index photonic modes also radiate strongly into the environment due to intrinsic symmetry properties. This has resulted in large losses in recent experimental realizations of this zero-index paradigm. Here, we propose a photonic crystal slab with zero-index modes which are also symmetry-protected bound states in the continuum. Our approach thus eliminates the associated radiation loss. This could enable, for the first time, large-scale integration of zero-index materials in photonic devices.
View details for DOI 10.1103/PhysRevLett.121.263901
View details for PubMedID 30636117
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Thermal meta-device in analogue of zero-index photonics.
Nature materials
2018
Abstract
Inspired by the developments in photonic metamaterials, the concept of thermal metamaterials has promised new avenues for manipulating the flow of heat. In photonics, the existence of natural materials with both positive and negative permittivities has enabled the creation of metamaterials with a very wide range of effective parameters. In contrast, in conductive heat transfer, the available range of thermal conductivities in natural materials is far narrower, strongly restricting the effective parameters of thermal metamaterials and limiting possible applications in extreme environments. Here, we identify a rigorous correspondence between zero index in Maxwell's equations and infinite thermal conductivity in Fourier's law. We also propose a conductive system with an integrated convective element that creates an extreme effective thermal conductivity, and hence by correspondence a thermal analogue of photonic near-zero-index metamaterials, a class of metamaterials with crucial importance in controlling light. Synergizing the general properties of zero-index metamaterials and the specific diffusive nature of thermal conduction, we theoretically and experimentally demonstrate a thermal zero-index cloak. In contrast with conventional thermal cloaks, this meta-device can operate in a highly conductive background and the cloaked object preserves great sensitivity to external temperature changes. Our work demonstrates a thermal metamaterial which greatly enhances the capability for molding the flow of heat.
View details for PubMedID 30510270
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Adjoint Method and Inverse Design for Nonlinear Nanophotonic Devices
ACS PHOTONICS
2018; 5 (12): 4781–87
View details for DOI 10.1021/acsphotonics.8b01522
View details for Web of Science ID 000454463000010
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Subwavelength angle-sensing photodetectors inspired by directional hearing in small animals (vol 13, pg 1143, 2018)
NATURE NANOTECHNOLOGY
2018; 13 (12): 1191
View details for DOI 10.1038/s41565-018-0322-9
View details for Web of Science ID 000452408300026
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Subwavelength angle-sensing photodetectors inspired by directional hearing in small animals
NATURE NANOTECHNOLOGY
2018; 13 (12): 1143-+
View details for DOI 10.1038/s41565-018-0278-9
View details for Web of Science ID 000452408300018
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Synthetic dimension in photonics
OPTICA
2018; 5 (11): 1396–1405
View details for DOI 10.1364/OPTICA.5.001396
View details for Web of Science ID 000450664900005
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Author Correction: Subwavelength angle-sensing photodetectors inspired by directional hearing in small animals.
Nature nanotechnology
2018
Abstract
In the version of this Letter originally published, Zongfu Yu was mistakenly not noted as being a corresponding author; this has now been corrected in all versions of the Letter.
View details for PubMedID 30443033
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Three-Dimensional Chiral Lattice Fermion in Floquet Systems.
Physical review letters
2018; 121 (19): 196401
Abstract
We show that the Nielsen-Ninomiya no-go theorem still holds on a Floquet lattice: there is an equal number of right-handed and left-handed Weyl points in a three-dimensional Floquet lattice. However, in the adiabatic limit, where the time evolution of the low-energy subspace is decoupled from the high-energy subspace, we show that the bulk dynamics in the low-energy subspace can be described by Floquet bands with extra left- or right-handed Weyl points, despite the no-go theorem. Assuming adiabatic evolution of two bands, we show that the difference of the number of right-handed and left-handed Weyl points equals twice the winding number of the adiabatic Floquet operator over the Brillouin zone. Based on these findings, we propose a realization of purely left- or right-handed Weyl particles on a 3D lattice using a Hamiltonian obtained through dimensional reduction of a four-dimensional quantum Hall system. We argue that the breakdown of the adiabatic approximation on the surface facilitates unusual closed orbits of wave packets in an applied magnetic field, which traverse alternatively through the low-energy and high-energy sector of the spectrum.
View details for DOI 10.1103/PhysRevLett.121.196401
View details for PubMedID 30468621
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Three-Dimensional Chiral Lattice Fermion in Floquet Systems
PHYSICAL REVIEW LETTERS
2018; 121 (19)
View details for DOI 10.1103/PhysRevLett.121.196401
View details for Web of Science ID 000449402500004
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Nonreciprocal Optical Dissipation Based on Direction-Dependent Rabi Splitting
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2018; 24 (6)
View details for DOI 10.1109/JSTQE.2018.2814792
View details for Web of Science ID 000435984500001
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Impact of objective bandwidth and frequency sampling density on search landscape structure and search performance in design optimization of optical structures
JOURNAL OF OPTICS
2018; 20 (11)
View details for DOI 10.1088/2040-8986/aadff4
View details for Web of Science ID 000446323800001
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Nonreciprocal Photonics Without Magneto-Optics
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
2018; 17 (11): 1948–52
View details for DOI 10.1109/LAWP.2018.2856258
View details for Web of Science ID 000451983000004
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Generate tensor network state by sequential single-photon scattering in waveguide QED systems
APL PHOTONICS
2018; 3 (11)
View details for DOI 10.1063/1.5044248
View details for Web of Science ID 000451738400011
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Subwavelength angle-sensing photodetectors inspired by directional hearing in small animals.
Nature nanotechnology
2018
Abstract
Sensing the direction of sounds gives animals clear evolutionary advantage. For large animals, with an ear-to-ear spacing that exceeds audible sound wavelengths, directional sensing is simply accomplished by recognizing the intensity and time differences of a wave impinging on its two ears1. Recent research suggests that in smaller, subwavelength animals, angle sensing can instead rely on a coherent coupling of soundwaves between the two ears2-4. Inspired by this natural design, here we show a subwavelength photodetection pixel that can measure both the intensity and incident angle of light. It relies on an electrical isolation and optical coupling of two closely spaced Si nanowires that support optical Mie resonances5-7. When these resonators scatter light into the same free-space optical modes, a non-Hermitian coupling results that affords highly sensitive angle determination. By straightforward photocurrent measurements, we can independently quantify the stored optical energy in each nanowire and relate the difference in the stored energy between the wires to the incident angle of a light wave. We exploit this effect to fabricate a subwavelength angle-sensitive pixel with angular sensitivity, deltatheta=0.32°.
View details for PubMedID 30374161
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Few-photon scattering and emission from low-dimensional quantum systems
PHYSICAL REVIEW B
2018; 98 (14)
View details for DOI 10.1103/PhysRevB.98.144112
View details for Web of Science ID 000448594100001
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Photonic thermal management of coloured objects.
Nature communications
2018; 9 (1): 4240
Abstract
The colours of outdoor structures, such as automobiles, buildings and clothing, are typically chosen for functional or aesthetic reasons. With a chosen colour, however, one must control the radiative thermal load for heating or cooling purposes. Here we provide a comprehensive calculation of the tunable range of radiative thermal load for all colours. The range exceeds 680Wm-2 for all colours, and can be as high as 866Wm-2, resulting from effects of metamerism, infrared solar absorption and radiative cooling. We experimentally demonstrate that two photonic structures with the same pink colour can have their temperatures differ by 47.6°C under sunlight. These structures are over 20°C either cooler or hotter than a commercial paint with a comparable colour. Furthermore, the hotter pink structure is 10°C hotter than a commercial black paint. These results elucidate the fundamental potentials of photonic thermal management for coloured objects.
View details for PubMedID 30315155
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Photonic thermal management of coloured objects
NATURE COMMUNICATIONS
2018; 9
View details for DOI 10.1038/s41467-018-06535-0
View details for Web of Science ID 000447123000016
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Unidirectional light transport in dynamically modulated waveguides
PHYSICAL REVIEW APPLIED
2018; 10 (4)
View details for DOI 10.1103/PhysRevApplied.10.044028
View details for Web of Science ID 000446915400002
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Enhanced high-harmonic generation from an all-dielectric metasurface
NATURE PHYSICS
2018; 14 (10): 1006-+
View details for DOI 10.1038/s41567-018-0233-6
View details for Web of Science ID 000446186700013
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A three-dimensional photonic topological insulator using a two-dimensional ring resonator lattice with a synthetic frequency dimension
SCIENCE ADVANCES
2018; 4 (10)
View details for DOI 10.1126/sciadv.aat2774
View details for Web of Science ID 000449221200014
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Isotropic wavevector domain image filters by a photonic crystal slab device
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
2018; 35 (10): 1685–91
View details for DOI 10.1364/JOSAA.35.001685
View details for Web of Science ID 000446029800004
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A three-dimensional photonic topological insulator using a two-dimensional ring resonator lattice with a synthetic frequency dimension.
Science advances
2018; 4 (10): eaat2774
Abstract
In the development of topological photonics, achieving three-dimensional topological insulators is of notable interest since it enables the exploration of new topological physics with photons and promises novel photonic devices that are robust against disorders in three dimensions. Previous theoretical proposals toward three-dimensional topological insulators use complex geometries that are challenging to implement. On the basis of the concept of synthetic dimension, we show that a two-dimensional array of ring resonators, which was previously demonstrated to exhibit a two-dimensional topological insulator phase, automatically becomes a three-dimensional topological insulator when the frequency dimension is taken into account. Moreover, by modulating a few of the resonators, a screw dislocation along the frequency axis can be created, which provides robust one-way transport of photons along the frequency axis. Demonstrating the physics of screw dislocation in a topological system has been a substantial challenge in solid-state systems. Our work indicates that the physics of three-dimensional topological insulators can be explored in standard integrated photonic platforms, leading to opportunities for novel devices that control the frequency of light.
View details for PubMedID 30345351
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MESH: A free electromagnetic solver for far-field and near-field radiative heat transfer for layered periodic structures
COMPUTER PHYSICS COMMUNICATIONS
2018; 231: 163–72
View details for DOI 10.1016/j.cpc.2018.04.032
View details for Web of Science ID 000437964200013
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Design of a tapered slot waveguide dielectric laser accelerator for sub-relativistic electrons
OPTICS EXPRESS
2018; 26 (18): 22801–15
Abstract
We propose a dielectric laser accelerator design based on a tapered slot waveguide structure for sub-relativistic electron acceleration. This tapering scheme allows for straightforward tuning of the phase velocity of the accelerating field along the propagation direction, which is necessary for maintaining synchronization with electrons as their velocities increase. Furthermore, the non-resonant nature of this design allows for better tolerance to experimental errors. We also introduce a method to design this continuously tapered structure based on the eikonal approximation, and give a working example based on realistic experimental parameters.
View details for DOI 10.1364/OE.26.022801
View details for Web of Science ID 000443431400037
View details for PubMedID 30184935
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Self-adaptive radiative cooling based on phase change materials
OPTICS EXPRESS
2018; 26 (18): A777–A787
Abstract
With the ability of harvesting the coldness of universe as a thermodynamic resource, radiative cooling technology is important for a broad range of applications such as passive building cooling, refrigeration, and renewable energy harvesting. However, all existing radiative cooling technologies utilize static structures, which lack the ability of self-adaptive tuning based on demand. Here we present the concept of self-adaptive radiative cooling based on phase change materials such as vanadium dioxide. We design a photonic structure that can adaptively turn 'on' and 'off' radiative cooling, depending the ambient temperature, without any extra energy input for switching. Our results here lead to new functionalities of radiative cooling and can potentially be used in a wide range of applications for the thermal managements of buildings, vehicles and textiles.
View details for DOI 10.1364/OE.26.00A777
View details for Web of Science ID 000443431400007
View details for PubMedID 30184837
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Spectrally Selective Nanocomposite Textile for Outdoor Personal Cooling
ADVANCED MATERIALS
2018; 30 (35)
View details for DOI 10.1002/adma.201802152
View details for Web of Science ID 000442732400018
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Polarization control with dielectric helix metasurfaces and arrays
OPTICS EXPRESS
2018; 26 (17): 21664–74
Abstract
Using band structure analysis and reflectance spectrum simulations, we show that dielectric helices exhibit strong circular dichroism and have polarization stop gaps for light propagating perpendicular to the helices, despite the lack of helical symmetry along this direction. We apply perturbation theory to quantitatively explain these effects. We also demonstrate that even for a single layer of dielectric helices similar phenomena exist. As a result, the helix array can operate as a dielectric chiral mirror. This dielectric chiral mirror can completely reflect normally incident light with one circular polarization (right- or left-handed as determined by the handedness of the helices) without changing the polarization's handedness while allowing light with the opposite circular polarization to be entirely transmitted.
View details for DOI 10.1364/OE.26.021664
View details for Web of Science ID 000442136200024
View details for PubMedID 30130869
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Pulse shortening in an actively mode-locked laser with parity-time symmetry
APL PHOTONICS
2018; 3 (8)
View details for DOI 10.1063/1.5039375
View details for Web of Science ID 000443758300001
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Near-Field Thermophotonic Systems for Low-Grade Waste-Heat Recovery
NANO LETTERS
2018; 18 (8): 5224–30
Abstract
Low-grade waste heat contains an enormous amount of exergy that can be recovered for renewable-energy generation. Current solid-state techniques for recovering low-grade waste heat, such as thermoelectric generators and thermophotovoltaics, however, are limited by low conversion efficiencies or power densities. In this work, we propose a solid-state near-field thermophotonic system. The system consists of a light-emitting diode (LED) on the hot side and a photovoltaic (PV) cell on the cold side. Part of the generated power by the PV cell is used to positively bias the LED. When operating in the near-field regime, the system can have power density and conversion efficiency significantly exceeding the performance of current solid-state approaches for low-grade waste-heat recovery. For example, when the gap spacing is 10 nm and the hot side and cold side are, respectively, 600 and 300 K, we show that the generated electric power density and thermal-to-electrical conversion efficiency can reach 9.6 W/cm2 and 9.8%, respectively, significantly outperforming the current record-setting thermoelectric generators. We identify the alignment of the band gaps of the LED and the PV cell, the appropriate choice of thickness of the LED and PV cell to mitigate the effect of non-radiative recombination, and the use of highly reflective back mirrors as key factors that affect the performance of the system. Our work points to the significant potential of photonic systems for the recovery of low-grade waste heat.
View details for DOI 10.1021/acs.nanolett.8b02184
View details for Web of Science ID 000441478300084
View details for PubMedID 30016115
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Relation between absorption and emission directivities for dipoles coupled with optical antennas
PHYSICAL REVIEW A
2018; 98 (1)
View details for DOI 10.1103/PhysRevA.98.013845
View details for Web of Science ID 000439972100013
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First-principles simulation of photonic crystal surface-emitting lasers using rigorous coupled wave analysis
APPLIED PHYSICS LETTERS
2018; 113 (4)
View details for DOI 10.1063/1.5045486
View details for Web of Science ID 000440046600006
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Training of photonic neural networks through in situ backpropagation and gradient measurement
OPTICA
2018; 5 (7): 864–71
View details for DOI 10.1364/OPTICA.5.000864
View details for Web of Science ID 000439429000016
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Spectrally Selective Nanocomposite Textile for Outdoor Personal Cooling.
Advanced materials (Deerfield Beach, Fla.)
2018: e1802152
Abstract
Outdoor heat stress poses a serious public health threat and curtails industrial labor supply and productivity, thus adversely impacting the wellness and economy of the entire society. With climate change, there will be more intense and frequent heat waves that further present a grand challenge for sustainability. However, an efficient and economical method that can provide localized outdoor cooling of the human body without intensive energy input is lacking. Here, a novel spectrally selective nanocomposite textile for radiative outdoor cooling using zinc oxide nanoparticle-embedded polyethylene is demonstrated. By reflecting more than 90% solar irradiance and selectively transmitting out human body thermal radiation, this textile can enable simulated skin to avoid overheating by 5-13 °C compared to normal textile like cotton under peak daylight condition. Owing to its superior passive cooling capability and compatibility with large-scale production, this radiative outdoor cooling textile is promising to widely benefit the sustainability of society in many aspects spanning from health to economy.
View details for PubMedID 30015999
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Accelerating convergence of iterative solution of finite difference frequency domain problems via schur complement domain decomposition
OPTICS EXPRESS
2018; 26 (13): 16925–39
View details for DOI 10.1364/OE.26.016925
View details for Web of Science ID 000436226800071
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Effective electric-field force for a photon in a synthetic frequency lattice created in a waveguide modulator
PHYSICAL REVIEW A
2018; 97 (6)
View details for DOI 10.1103/PhysRevA.97.063838
View details for Web of Science ID 000435439900009
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Nanophotonic control of thermal radiation for energy applications [Invited]
OPTICS EXPRESS
2018; 26 (12): 15995–6021
View details for DOI 10.1364/OE.26.015995
View details for Web of Science ID 000435068300100
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Size Scaling of Photonic Crystal Surface Emitting Lasers on Silicon Substrates
IEEE PHOTONICS JOURNAL
2018; 10 (3)
View details for DOI 10.1109/JPHOT.2018.2829900
View details for Web of Science ID 000432477300001
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On-Chip Laser-Power Delivery System for Dielectric Laser Accelerators
PHYSICAL REVIEW APPLIED
2018; 9 (5)
View details for DOI 10.1103/PhysRevApplied.9.054017
View details for Web of Science ID 000433002200001
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Broadband Control of Topological Nodes in Electromagnetic Fields
PHYSICAL REVIEW LETTERS
2018; 120 (19): 193903
Abstract
We study topological nodes (phase singularities) in electromagnetic wave interactions with structures. We show that, when the nodes exist, it is possible to bind certain nodes to a specific plane in the structure by a combination of mirror and time-reversal symmetry. Such binding does not rely on any resonances in the structure. As a result, the nodes persist on the plane over a wide wavelength range. As an implication of such broadband binding, we demonstrate that the topological nodes can be used for hiding of metallic objects over a broad wavelength range.
View details for PubMedID 29799227
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Electroluminescent refrigeration by ultra-efficient GaAs light-emitting diodes
JOURNAL OF APPLIED PHYSICS
2018; 123 (17)
View details for DOI 10.1063/1.5019764
View details for Web of Science ID 000431651600004
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Thermodynamic limits of energy harvesting from outgoing thermal radiation
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2018; 115 (16): E3609–E3615
Abstract
We derive the thermodynamic limits of harvesting power from the outgoing thermal radiation from the ambient to the cold outer space. The derivations are based on a duality relation between thermal engines that harvest solar radiation and those that harvest outgoing thermal radiation. In particular, we derive the ultimate limit for harvesting outgoing thermal radiation, which is analogous to the Landsberg limit for solar energy harvesting, and show that the ultimate limit far exceeds what was previously thought to be possible. As an extension of our work, we also derive the ultimate limit of efficiency of thermophotovoltaic systems.
View details for PubMedID 29610347
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Low index contrast heterostructure photonic crystal cavities with high quality factors and vertical radiation coupling
APPLIED PHYSICS LETTERS
2018; 112 (14)
View details for DOI 10.1063/1.5026433
View details for Web of Science ID 000429344100005
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Response to "Comment on 'High-performance near-field electroluminescent refrigeration device consisting of a GaAs light emitting diode and a Si photovoltaic cell'" [J. Appl. Phys. 122, 143104 (2017)]
JOURNAL OF APPLIED PHYSICS
2018; 123 (11)
View details for DOI 10.1063/1.5023511
View details for Web of Science ID 000428070900055
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Photonic crystal slab Laplace operator for image differentiation
OPTICA
2018; 5 (3): 251–56
View details for DOI 10.1364/OPTICA.5.000251
View details for Web of Science ID 000428145500005
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Synthetic space with arbitrary dimensions in a few rings undergoing dynamic modulation
PHYSICAL REVIEW B
2018; 97 (10)
View details for DOI 10.1103/PhysRevB.97.104105
View details for Web of Science ID 000427798800001
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Theory of many-body radiative heat transfer without the constraint of reciprocity
PHYSICAL REVIEW B
2018; 97 (9)
View details for DOI 10.1103/PhysRevB.97.094302
View details for Web of Science ID 000426775200003
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Metamaterials for radiative sky cooling
NATIONAL SCIENCE REVIEW
2018; 5 (2): 132–33
View details for DOI 10.1093/nsr/nwy012
View details for Web of Science ID 000428637600006
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Optimization of Multilayer Optical Films with a Memetic Algorithm and Mixed Integer Programming
ACS PHOTONICS
2018; 5 (3): 684–91
View details for DOI 10.1021/acsphotonics.7b01136
View details for Web of Science ID 000428356400003
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Enhancing Mo:BiVO4 Solar Water Splitting with Patterned Au Nanospheres by Plasmon-Induced Energy Transfer
ADVANCED ENERGY MATERIALS
2018; 8 (5)
View details for DOI 10.1002/aenm.201701765
View details for Web of Science ID 000425113600016
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Effects of non-Hermitian perturbations on Weyl Hamiltonians with arbitrary topological charges
PHYSICAL REVIEW B
2018; 97 (7)
View details for DOI 10.1103/PhysRevB.97.075128
View details for Web of Science ID 000424901800005
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Localization and time-reversal of light through dynamic modulation
PHYSICAL REVIEW B
2018; 97 (6)
View details for DOI 10.1103/PhysRevB.97.060301
View details for Web of Science ID 000424744900001
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Significant Enhancement of Near-Field Electromagnetic Heat Transfer in a Multilayer Structure through Multiple Surface-States Coupling
PHYSICAL REVIEW LETTERS
2018; 120 (6): 063901
Abstract
We show that near-field electromagnetic heat transfer between multilayer thermal bodies can be significantly enhanced by the contributions of surface states at multiple surfaces. As a demonstration, we show that when one of the materials forming the multilayer structure is described by the Drude model, and the other one is a vacuum, at the same gap spacing the resulting heat transfer can be up to 40 times higher as compared to that between two semi-infinite materials described by the same Drude model. Moreover, this system can exhibit a nonmonotonic dependency in its heat transfer coefficient as a function of the middle gap spacing. The enhancement effect in the system persists for realistic materials.
View details for PubMedID 29481235
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Adjoint-based optimization of active nanophotonic devices
OPTICS EXPRESS
2018; 26 (3): 3236–48
Abstract
We show that the adjoint variable method can be combined with the multi-frequency finite-difference frequency-domain method for efficient sensitivity calculations, enabling the systematic optimization of active nanophotonic devices. As a proof of principle demonstration, we have optimized a dynamic isolator structure in two-dimensions, resulting in the reduction of the length of the modulated regions by a factor of two, while retaining good performance in the isolation ratio and insertion loss.
View details for DOI 10.1364/OE.26.003236
View details for Web of Science ID 000425365900097
View details for PubMedID 29401854
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Nanoporous polyethylene microfibres for large-scale radiative cooling fabric
NATURE SUSTAINABILITY
2018; 1 (2): 105–12
View details for DOI 10.1038/s41893-018-0023-2
View details for Web of Science ID 000439122700012
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Anti-Hermitian photodetector facilitating efficient subwavelength photon sorting
NATURE COMMUNICATIONS
2018; 9: 316
Abstract
The ability to split an incident light beam into separate wavelength bands is central to a diverse set of optical applications, including imaging, biosensing, communication, photocatalysis, and photovoltaics. Entirely new opportunities are currently emerging with the recently demonstrated possibility to spectrally split light at a subwavelength scale with optical antennas. Unfortunately, such small structures offer limited spectral control and are hard to exploit in optoelectronic devices. Here, we overcome both challenges and demonstrate how within a single-layer metafilm one can laterally sort photons of different wavelengths below the free-space diffraction limit and extract a useful photocurrent. This chipscale demonstration of anti-Hermitian coupling between resonant photodetector elements also facilitates near-unity photon-sorting efficiencies, near-unity absorption, and a narrow spectral response (∼ 30 nm) for the different wavelength channels. This work opens up entirely new design paradigms for image sensors and energy harvesting systems in which the active elements both sort and detect photons.
View details for PubMedID 29358626
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Nonreciprocal optical manipulation using dynamic modulation
IEEE. 2018
View details for Web of Science ID 000426986100030
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Analysis of an Anti-reflecting Nanowire Transparent Electrode for Solar Cells
IEEE. 2018
View details for Web of Science ID 000526031000151
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Near-field thermo-photovoltaic platform
IEEE. 2018
View details for Web of Science ID 000526031001051
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A Large Area Monolayer WS2 Laser Based on Surface-Emitting Heterostructure Photonic Crystal Cavities
IEEE. 2018
View details for Web of Science ID 000526031001403
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A Photonic Crystal Slab Laplace Differentiator
IEEE. 2018
View details for Web of Science ID 000526031000188
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Effects of non-Hermitian perturbations on Weyl Hamiltonians with arbitrary topological charges
IEEE. 2018
View details for Web of Science ID 000526031000343
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Photonic Chern insulator through homogenization of an array of particles
IEEE. 2018
View details for Web of Science ID 000526031000387
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Memetic Algorithm Optimization of Thin-film Photonic Structures for Thermal and Energy Applications
IEEE. 2018
View details for Web of Science ID 000526031002304
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Localization, Time-reversal, and Unidirectional Guiding of Light Pulses Using Dynamic Modulation
IEEE. 2018
View details for Web of Science ID 000526031000286
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Enhanced Solid-State High-Harmonic Generation from a Silicon Metasurface
IEEE. 2018
View details for Web of Science ID 000526031000278
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Spontaneous and Stimulated Emission from Quantum Optical Systems
IEEE. 2018
View details for Web of Science ID 000526031001206
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Broadband Control of Topological Nodes in Electromagnetic Fields
IEEE. 2018
View details for Web of Science ID 000526031001056
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Achieving Topological Photonics in a Synthetic Space with Dynamically Modulated Ring Resonators
IEEE. 2018
View details for Web of Science ID 000526031003400
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Complete photonic bandgaps in supercell photonic crystals
IEEE. 2018
View details for Web of Science ID 000526031003128
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Scaling towards Efficient Monolayer WS2 Photonic Crystal Lasers
IEEE. 2018: 21–22
View details for Web of Science ID 000455155000012
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Non-Hermitian and topological electromagnetics: synthetic dimensions, and robust wireless power transfer
IEEE. 2018: 19
View details for Web of Science ID 000455155000011
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Direct Measurement of Directional Emission from Monolayer WS2 Laser with Heterostructure Photonic Crystal Cavities
IEEE. 2018
View details for Web of Science ID 000460542800120
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Design of Light-Emitting Diodes and Photovoltaic Cells for Electroluminescent Refrigeration
IEEE. 2018: 1868–U1094
View details for Web of Science ID 000469200401196
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Decoupled textures for broadband absorption enhancement beyond Lambertian light trapping limit in thin-film silicon-based solar cells
IEEE. 2018: 3455–59
View details for Web of Science ID 000469200403114
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Room Temperature Photonic Crystal Surface Emitting Laser with Synthesized Monolayer Tungsten Disulfide
IEEE. 2018: 167–68
View details for Web of Science ID 000450800100082
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Complete photonic band gaps in supercell photonic crystals
PHYSICAL REVIEW A
2017; 96 (5)
View details for DOI 10.1103/PhysRevA.96.051802
View details for Web of Science ID 000414951500003
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High-performance near-field thermophotovoltaics for waste heat recovery
NANO ENERGY
2017; 41: 344–50
View details for DOI 10.1016/j.nanoen.2017.09.054
View details for Web of Science ID 000415302600037
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A dual-mode textile for human body radiative heating and cooling
SCIENCE ADVANCES
2017; 3 (11): e1700895
Abstract
Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textile without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. Numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.
View details for PubMedID 29296678
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Creating anyons from photons using a nonlinear resonator lattice subject to dynamic modulation
PHYSICAL REVIEW A
2017; 96 (4)
View details for DOI 10.1103/PhysRevA.96.043864
View details for Web of Science ID 000413846400007
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High-performance near-field electroluminescent refrigeration device consisting of a GaAs light emitting diode and a Si photovoltaic cell
JOURNAL OF APPLIED PHYSICS
2017; 122 (14)
View details for DOI 10.1063/1.5007712
View details for Web of Science ID 000413038500004
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Thermal Photonics and Energy Applications
JOULE
2017; 1 (2): 264–73
View details for DOI 10.1016/j.joule.2017.07.012
View details for Web of Science ID 000425180300012
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Exergy in near-field electromagnetic heat transfer
JOURNAL OF APPLIED PHYSICS
2017; 122 (12)
View details for DOI 10.1063/1.5004662
View details for Web of Science ID 000412099600024
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Photonic Chern insulator through homogenization of an array of particles
PHYSICAL REVIEW B
2017; 96 (10)
View details for DOI 10.1103/PhysRevB.96.100202
View details for Web of Science ID 000411982600001
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Warming up human body by nanoporous metallized polyethylene textile
NATURE COMMUNICATIONS
2017; 8: 496
Abstract
Space heating accounts for the largest energy end-use of buildings that imposes significant burden on the society. The energy wasted for heating the empty space of the entire building can be saved by passively heating the immediate environment around the human body. Here, we demonstrate a nanophotonic structure textile with tailored infrared (IR) property for passive personal heating using nanoporous metallized polyethylene. By constructing an IR-reflective layer on an IR-transparent layer with embedded nanopores, the nanoporous metallized polyethylene textile achieves a minimal IR emissivity (10.1%) on the outer surface that effectively suppresses heat radiation loss without sacrificing wearing comfort. This enables 7.1 °C decrease of the set-point compared to normal textile, greatly outperforming other radiative heating textiles by more than 3 °C. This large set-point expansion can save more than 35% of building heating energy in a cost-effective way, and ultimately contribute to the relief of global energy and climate issues.Energy wasted for heating the empty space of the entire building can be saved by passively heating the immediate environment around the human body. Here, the authors show a nanophotonic structure textile with tailored infrared property for passive personal heating using nanoporous metallized polyethylene.
View details for PubMedID 28928427
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Sub-ambient non-evaporative fluid cooling with the sky
NATURE ENERGY
2017; 2 (9)
View details for DOI 10.1038/nenergy.2017.143
View details for Web of Science ID 000415189100014
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Unidirectional reflectionless light propagation at exceptional points
NANOPHOTONICS
2017; 6 (5): 977-996
View details for DOI 10.1515/nanoph-2017-0019
View details for Web of Science ID 000407233400010
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Electrodeposited high strength, thermally stable spectrally selective rhenium nickel inverse opals
NANOSCALE
2017; 9 (31): 11187–94
Abstract
Rhenium-Nickel (RexNi100-x) based 3D metallic inverse opals (IOs) were realized via colloidal crystal templated electrodeposition from an aqueous electrolyte. By varying the electrodeposition parameters, x could be varied from 0 to 88. Under reducing conditions, the rhenium-rich IOs were structurally stable to temperatures of at least 1000 °C for 5 h and for at least 12 h after coating with a thin layer of Al2O3. This demonstrated level of thermal stability is significantly improved compared to previously reported electrodeposited refractory inverse opals with similar characteristic dimensions. A strong frequency dependence in the optical reflection, which ranged from ∼5% around 1.5 μm to ∼65% around 5 μm, is predicted by simulations and experimentally observed, indicating the potential of this structure as a high temperature spectrally selective optical absorber/emitter. The elastic modulus of the ReNi IO structure is ∼35 GPa and the hardness is ∼0.8 GPa. Both these properties are much higher than those of Ni inverse opals and other periodically porous materials with similar characteristic pore dimensions. We suggest this work provides a promising approach for thermally stable mesostructured materials for high temperature catalyst supports, refractory photonics and mechanical applications including high temperature filtration, and high temperature actuators.
View details for DOI 10.1039/c7nr03567e
View details for Web of Science ID 000407336600024
View details for PubMedID 28749496
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Theory of solar cell light trapping through a nonequilibrium Green's function formulation of Maxwell's equations
PHYSICAL REVIEW B
2017; 96 (3)
View details for DOI 10.1103/PhysRevB.96.035304
View details for Web of Science ID 000405509400005
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Objective-trait-bias metaheuristics for design optimization of optical structures
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2017; 34 (7): 1551-1559
View details for DOI 10.1364/JOSAB.34.001551
View details for Web of Science ID 000407823200046
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Exact solution to the steady-state dynamics of a periodically modulated resonator
APL PHOTONICS
2017; 2 (7)
View details for DOI 10.1063/1.4985381
View details for Web of Science ID 000406761000003
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Optical Circulation and Isolation Based on Indirect Photonic Transitions of Guided Resonance Modes
ACS PHOTONICS
2017; 4 (7): 1639–45
View details for DOI 10.1021/acsphotonics.7b00420
View details for Web of Science ID 000406174600010
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Near-field heat transfer between graphene/hBN multilayers
PHYSICAL REVIEW B
2017; 95 (24)
View details for DOI 10.1103/PhysRevB.95.245437
View details for Web of Science ID 000404470200013
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Method for computationally efficient design of dielectric laser accelerator structures
OPTICS EXPRESS
2017; 25 (13): 15414–27
Abstract
Dielectric microstructures have generated much interest in recent years as a means of accelerating charged particles when powered by solid state lasers. The acceleration gradient (or particle energy gain per unit length) is an important figure of merit. To design structures with high acceleration gradients, we explore the adjoint variable method, a highly efficient technique used to compute the sensitivity of an objective with respect to a large number of parameters. With this formalism, the sensitivity of the acceleration gradient of a dielectric structure with respect to its entire spatial permittivity distribution is calculated by the use of only two full-field electromagnetic simulations, the original and 'adjoint'. The adjoint simulation corresponds physically to the reciprocal situation of a point charge moving through the accelerator gap and radiating. Using this formalism, we perform numerical optimizations aimed at maximizing acceleration gradients, which generate fabricable structures of greatly improved performance in comparison to previously examined geometries.
View details for DOI 10.1364/OE.25.015414
View details for Web of Science ID 000404189800133
View details for PubMedID 28788967
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Robust wireless power transfer using a nonlinear parity-time-symmetric circuit
NATURE
2017; 546 (7658): 387-+
Abstract
Considerable progress in wireless power transfer has been made in the realm of non-radiative transfer, which employs magnetic-field coupling in the near field. A combination of circuit resonance and impedance transformation is often used to help to achieve efficient transfer of power over a predetermined distance of about the size of the resonators. The development of non-radiative wireless power transfer has paved the way towards real-world applications such as wireless powering of implantable medical devices and wireless charging of stationary electric vehicles. However, it remains a fundamental challenge to create a wireless power transfer system in which the transfer efficiency is robust against the variation of operating conditions. Here we propose theoretically and demonstrate experimentally that a parity-time-symmetric circuit incorporating a nonlinear gain saturation element provides robust wireless power transfer. Our results show that the transfer efficiency remains near unity over a distance variation of approximately one metre, without the need for any tuning. This is in contrast with conventional methods where high transfer efficiency can only be maintained by constantly tuning the frequency or the internal coupling parameters as the transfer distance or the relative orientation of the source and receiver units is varied. The use of a nonlinear parity-time-symmetric circuit should enable robust wireless power transfer to moving devices or vehicles.
View details for PubMedID 28617463
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Generalized cluster decomposition principle illustrated in waveguide quantum electrodynamics
PHYSICAL REVIEW A
2017; 95 (6)
View details for DOI 10.1103/PhysRevA.95.063809
View details for Web of Science ID 000402967400008
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Plasmonic computing of spatial differentiation
NATURE COMMUNICATIONS
2017; 8
Abstract
Optical analog computing offers high-throughput low-power-consumption operation for specialized computational tasks. Traditionally, optical analog computing in the spatial domain uses a bulky system of lenses and filters. Recent developments in metamaterials enable the miniaturization of such computing elements down to a subwavelength scale. However, the required metamaterial consists of a complex array of meta-atoms, and direct demonstration of image processing is challenging. Here, we show that the interference effects associated with surface plasmon excitations at a single metal-dielectric interface can perform spatial differentiation. And we experimentally demonstrate edge detection of an image without any Fourier lens. This work points to a simple yet powerful mechanism for optical analog computing at the nanoscale.
View details for DOI 10.1038/ncomms15391
View details for Web of Science ID 000401628400001
View details for PubMedID 28524882
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Non-reciprocal geometric phase in nonlinear frequency conversion
OPTICS LETTERS
2017; 42 (10): 1990-1993
Abstract
We describe analytically and numerically the geometric phase arising from nonlinear frequency conversion and show that such a phase can be made non-reciprocal by momentum-dependent photonic transition. Such non-reciprocity is immune to the shortcomings imposed by dynamic reciprocity in Kerr and Kerr-like devices. We propose a simple and practical implementation, requiring only a single waveguide and one pump, while the geometric phase is controllable by the pump and promises robustness against fabrication errors.
View details for DOI 10.1364/OL.42.001990
View details for Web of Science ID 000401424900031
View details for PubMedID 28504731
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Universal modal radiation laws for all thermal emitters
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2017; 114 (17): 4336-4341
Abstract
We derive four laws relating the absorptivity and emissivity of thermal emitters. Unlike the original Kirchhoff radiation law derivations, these derivations include diffraction, and so are valid also for small objects, and can also cover nonreciprocal objects. The proofs exploit two recent approaches. First, we express all fields in terms of the mode-converter basis sets of beams; these sets, which can be uniquely established for any linear optical object, give orthogonal input beams that are coupled one-by-one to orthogonal output beams. Second, we consider thought experiments using universal linear optical machines, which allow us to couple appropriate beams and black bodies. Two of these laws can be regarded as rigorous extensions of previously known laws: One gives a modal version of a radiation law for reciprocal objects-the absorptivity of any input beam equals the emissivity into the "backward" (i.e., phase-conjugated) version of that beam; another gives the overall equality of the sums of the emissivities and the absorptivities for any object, including nonreciprocal ones. The other two laws, valid for reciprocal and nonreciprocal objects, are quite different from previous relations. One shows universal equivalence of the absorptivity of each mode-converter input beam and the emissivity into its corresponding scattered output beam. The other gives unexpected equivalences of absorptivity and emissivity for broad classes of beams. Additionally, we prove these orthogonal mode-converter sets of input and output beams are the ones that maximize absorptivities and emissivities, respectively, giving these beams surprising additional physical meaning.
View details for DOI 10.1073/pnas.1701606114
View details for Web of Science ID 000399995600040
View details for PubMedID 28396436
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A Comprehensive Photonic Approach for Solar Cell Cooling
ACS PHOTONICS
2017; 4 (4): 774-782
View details for DOI 10.1021/acsphotonics.7b00089
View details for Web of Science ID 000399968500010
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Analysis of an anti-reflecting nanowire transparent electrode for solar cells
JOURNAL OF APPLIED PHYSICS
2017; 121 (11)
View details for DOI 10.1063/1.4978769
View details for Web of Science ID 000397421400009
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Planar, Ultrathin, Subwavelength Spectral Light Separator for Efficient, Wide-Angle Spectral Imaging
ACS PHOTONICS
2017; 4 (3): 525-535
View details for DOI 10.1021/acsphotonics.6b00705
View details for Web of Science ID 000396808000018
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Synthetic gauge potential and effective magnetic field in a Raman medium undergoing molecular modulation
PHYSICAL REVIEW A
2017; 95 (3)
View details for DOI 10.1103/PhysRevA.95.033801
View details for Web of Science ID 000395980600003
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Daytime Radiative Cooling Using Near-Black Infrared Emitters
ACS PHOTONICS
2017; 4 (3): 626-630
View details for DOI 10.1021/acsphotonics.6b00991
View details for Web of Science ID 000396808000031
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Invited Article: Acousto-optic finite-difference frequency- domain algorithm for first-principles simulations of on-chip acousto-optic devices
APL PHOTONICS
2017; 2 (2)
View details for DOI 10.1063/1.4975002
View details for Web of Science ID 000395386300001
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Subwavelength Angle Sensing Photodetector
IEEE. 2017
View details for Web of Science ID 000427296202462
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Frequency-axis light transport and topological effects in dynamic photonic structures
SPIE-INT SOC OPTICAL ENGINEERING. 2017
View details for DOI 10.1117/12.2257705
View details for Web of Science ID 000399924900014
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Efficient electroluminescent cooling with a light-emitting diode coupled to a photovoltaic cell (Conference Presentation)
SPIE-INT SOC OPTICAL ENGINEERING. 2017
View details for DOI 10.1117/12.2252631
View details for Web of Science ID 000404886900004
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Systematic Thermalphotovoltaic Solar Cell Optimization
IEEE. 2017: 2732-2735
View details for Web of Science ID 000455636002173
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Electro-Luminescent Refrigeration Enabled by Highly Efficient Photovoltaics
IEEE. 2017: 2185-+
View details for Web of Science ID 000455636002045
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Achieving Arbitrary Control over Pairs of Polarization States Using Complex Birefringent Metamaterials.
Physical review letters
2017; 118 (25): 253902
Abstract
We demonstrate that the key to realizing arbitrary control over pairs of polarization states of light, i.e., transforming an arbitrarily polarized pair of input states to an arbitrarily polarized pair of output states, is the ability to generate pairs of states with orthogonal polarizations from nonorthogonal pairs of initial states. Then, we develop a new class of non-Hermitian metamaterials, termed complex birefringent metamaterials, which are able to do exactly this. Such materials could facilitate the detection of small polarization changes in scattering experiments as well as enable new polarization multiplexing schemes in communications networks.
View details for PubMedID 28696764
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Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion.
Scientific reports
2017; 7 (1): 5362
Abstract
Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In field tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. With straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat.
View details for PubMedID 28706230
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Topologically Protected Complete Polarization Conversion.
Physical review letters
2017; 119 (16): 167401
Abstract
We consider the process of conversion between linear polarizations as light is reflected from a photonic crystal slab. We observe that, over a wide range of frequencies, complete polarization conversion can be found at isolated wave vectors. Moreover, such an effect is topological: the complex reflection coefficients have a nonzero winding number in the wave vector space. We also show that bound states in continuum in this system have their wave vectors lying on the critical coupling curve that defines the condition for complete polarization conversion. Our work points to the use of topological photonics concepts for the control of polarization, and suggests the exploration of topological properties of scattering matrices as a route towards creating robust optical devices.
View details for PubMedID 29099196
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Enhancing Near-Field Radiative Heat Transfer with Si-based Metasurfaces.
Physical review letters
2017; 118 (20): 203901
Abstract
We demonstrate in this work that the use of metasurfaces provides a viable strategy to largely tune and enhance near-field radiative heat transfer between extended structures. In particular, using a rigorous coupled wave analysis, we predict that Si-based metasurfaces featuring two-dimensional periodic arrays of holes can exhibit a room-temperature near-field radiative heat conductance much larger than any unstructured material to date. We show that this enhancement, which takes place in a broad range of separations, relies on the possibility to largely tune the properties of the surface plasmon polaritons that dominate the radiative heat transfer in the near-field regime.
View details for PubMedID 28581797
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Enhanced Light Emission from MoS2 in Heterostructure Photonic Crystal Cavities
IEEE. 2017: 461–62
View details for Web of Science ID 000426792600202
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Passive Cooling of Solar Cells with a Comprehensive Photonic Approach
IEEE. 2017: 847–50
View details for Web of Science ID 000424694700212
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A Multi-frequency Finite-difference Frequency-domain Algorithm for Active Nanophotonic Device Simulations
IEEE. 2017
View details for Web of Science ID 000427296200467
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Lateral Size Scaling of Photonic Crystal Surface-Emitting Lasers on Si
IEEE. 2017
View details for Web of Science ID 000427296202063
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Eigenvalue dynamics in the presence of non-uniform gain and loss
IEEE. 2017
View details for Web of Science ID 000427296200245
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Theory of few-photon quantum scattering in nanophotonic structures
SPIE-INT SOC OPTICAL ENGINEERING. 2017
View details for DOI 10.1117/12.2261178
View details for Web of Science ID 000404881800010
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Photonic Weyl Point in a 2D Resonator Array with a Synthetic Frequency Dimension
IEEE. 2017
View details for Web of Science ID 000427296200309
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Hot Carrier-Based Near-Field Thermophotovoltaic Energy Conversion.
ACS nano
2017; 11 (3): 3001–9
Abstract
Near-field thermophotovoltaics (NFTPV) is a promising approach for direct conversion of heat to electrical power. This technology relies on the drastic enhancement of radiative heat transfer (compared to conventional blackbody radiation) that occurs when objects at different temperatures are brought to deep subwavelength distances (typically <100 nm) from each other. Achieving such radiative heat transfer between a hot object and a photovoltaic (PV) cell could allow direct conversion of heat to electricity with a greater efficiency than using current solid-state technologies (e.g., thermoelectric generators). One of the main challenges in the development of this technology, however, is its incompatibility with conventional silicon PV cells. Thermal radiation is weak at frequencies larger than the ∼1.1 eV bandgap of silicon, such that PV cells with lower excitation energies (typically 0.4-0.6 eV) are required for NFTPV. Using low bandgap III-V semiconductors to circumvent this limitation, as proposed in most theoretical works, is challenging and therefore has never been achieved experimentally. In this work, we show that hot carrier PV cells based on Schottky junctions between silicon and metallic films could provide an attractive solution for achieving high efficiency NFTPV electricity generation. Hot carrier science is currently an important field of research and several approaches are investigated for increasing the quantum efficiency (QE) of hot carrier generation beyond conventional Fowler model predictions. If the Fowler limit can indeed be overcome, we show that hot carrier-based NFTPV systems-after optimization of their thermal radiation spectrum-could allow electricity generation with up to 10-30% conversion efficiencies and 10-500 W/cm2 generated power densities (at 900-1500 K temperatures). We also discuss how the unique properties of thermal radiation in the extreme near-field are especially well suited for investigating recently proposed approaches for high QE hot carrier junctions. We therefore expect our work to be of interest for the field of hot carrier science and-by relying solely on conventional thin film materials-to provide a path for the experimental demonstration of NFTPV energy conversion.
View details for PubMedID 28287714
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Narrowband thermal emission from a uniform tungsten surface critically coupled with a photonic crystal guided resonance
OPTICS EXPRESS
2016; 24 (26): 29896-29907
Abstract
We numerically demonstrate narrowband thermal emission with unity emissivity peak in the near-infrared range by critically coupling a flat tungsten surface with guided resonances of a dielectric photonic crystal slab. The tungsten surface is separated from the photonic crystal slab by a vacuum gap. The structure possesses significant tunability for both the center frequency and the linewidth of the thermal emission band. Moreover, the tungsten surface, being un-structured, should exhibit enhanced thermal stability at elevated temperature as compared to tungsten nanostructures.
View details for DOI 10.1364/OE.24.029896
View details for Web of Science ID 000390809100062
View details for PubMedID 28059374
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Nonequilibrium Casimir Force with a Nonzero Chemical Potential for Photons
PHYSICAL REVIEW LETTERS
2016; 117 (26)
Abstract
We introduce a new class of nonequilibrium Casimir forces, where the deviation from equilibrium is achieved through the use of a nonzero chemical potential of photons. Such a force can be observed when two semiconductors are brought in close proximity to each other, and when at least one of the semiconductors is subject to an external voltage. By exact numerical calculations of a sphere-plate configuration, we show that in the total force the non-equilibrium component can dominate over its equilibrium counterpart with a relatively modest external voltage, even when the sphere-plate separation is in the nanoscale. As a result, repulsion can be achieved at the nanoscale even with a relatively modest applied voltage. The results here point to a pathway that can significantly advance the quest for observing and harnessing nonequilibrium Casimir forces in solid-state systems.
View details for DOI 10.1103/PhysRevLett.117.267401
View details for Web of Science ID 000390301300004
View details for PubMedID 28059546
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Effects of non-uniform distributions of gain and loss in photonic crystals
NEW JOURNAL OF PHYSICS
2016; 18
View details for DOI 10.1088/1367-2630/18/12/125007
View details for Web of Science ID 000391535700001
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Photonic Weyl point in a two-dimensional resonator lattice with a synthetic frequency dimension
NATURE COMMUNICATIONS
2016; 7
Abstract
Weyl points, as a signature of 3D topological states, have been extensively studied in condensed matter systems. Recently, the physics of Weyl points has also been explored in electromagnetic structures such as photonic crystals and metamaterials. These structures typically have complex three-dimensional geometries, which limits the potential for exploring Weyl point physics in on-chip integrated systems. Here we show that Weyl point physics emerges in a system of two-dimensional arrays of resonators undergoing dynamic modulation of refractive index. In addition, the phase of modulation can be controlled to explore Weyl points under different symmetries. Furthermore, unlike static structures, in this system the non-trivial topology of the Weyl point manifests in terms of surface state arcs in the synthetic space that exhibit one-way frequency conversion. Our system therefore provides a versatile platform to explore and exploit Weyl point physics on chip.
View details for DOI 10.1038/ncomms13731
View details for Web of Science ID 000390283700001
View details for PubMedID 27976714
View details for PubMedCentralID PMC5172232
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Radiative cooling to deep sub-freezing temperatures through a 24-h day-night cycle
NATURE COMMUNICATIONS
2016; 7
Abstract
Radiative cooling technology utilizes the atmospheric transparency window (8-13 μm) to passively dissipate heat from Earth into outer space (3 K). This technology has attracted broad interests from both fundamental sciences and real world applications, ranging from passive building cooling, renewable energy harvesting and passive refrigeration in arid regions. However, the temperature reduction experimentally demonstrated, thus far, has been relatively modest. Here we theoretically show that ultra-large temperature reduction for as much as 60 °C from ambient is achievable by using a selective thermal emitter and by eliminating parasitic thermal load, and experimentally demonstrate a temperature reduction that far exceeds previous works. In a populous area at sea level, we have achieved an average temperature reduction of 37 °C from the ambient air temperature through a 24-h day-night cycle, with a maximal reduction of 42 °C that occurs when the experimental set-up enclosing the emitter is exposed to peak solar irradiance.
View details for DOI 10.1038/ncomms13729
View details for Web of Science ID 000389627000001
View details for PubMedID 27959339
View details for PubMedCentralID PMC5159822
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Understanding search behavior via search landscape analysis in design optimization of optical structures
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2016; 33 (12): 2457-2471
View details for DOI 10.1364/JOSAB.33.002457
View details for Web of Science ID 000390404400026
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Photonic Structure Textile Design for Localized Thermal Cooling Based on a Fiber Blending Scheme
ACS PHOTONICS
2016; 3 (12): 2420-2426
View details for DOI 10.1021/acsphotonics.6b00644
View details for Web of Science ID 000390731700032
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Temporal coupled mode theory linking to surface-wave dispersion relations in near-field electromagnetic heat transfer
JOURNAL OF APPLIED PHYSICS
2016; 120 (19)
View details for DOI 10.1063/1.4967832
View details for Web of Science ID 000388958200013
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Multi-frequency finite-difference frequency-domain algorithm for active nanophotonic device simulations
OPTICA
2016; 3 (11): 1256-1259
View details for DOI 10.1364/OPTICA.3.001256
View details for Web of Science ID 000388975200016
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Time reversal of a wave packet with temporal modulation of gauge potential
PHYSICAL REVIEW B
2016; 94 (14)
View details for DOI 10.1103/PhysRevB.94.140303
View details for Web of Science ID 000389708300001
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Fano interference in two-photon transport
PHYSICAL REVIEW A
2016; 94 (4)
View details for DOI 10.1103/PhysRevA.94.043826
View details for Web of Science ID 000385980600015
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Eigenvalue dynamics in the presence of nonuniform gain and loss
PHYSICAL REVIEW A
2016; 94 (3)
View details for DOI 10.1103/PhysRevA.94.033857
View details for Web of Science ID 000384374500009
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Persistent Directional Current at Equilibrium in Nonreciprocal Many-Body Near Field Electromagnetic Heat Transfer
PHYSICAL REVIEW LETTERS
2016; 117 (13)
Abstract
We consider the consequence of nonreciprocity in near-field heat transfer by studying systems consisting of magneto-optical nanoparticles. We demonstrate that, in thermal equilibrium, a nonreciprocal many-body system in heat transfer can support a persistent directional heat current, without violating the second law of thermodynamics. Such a persistent directional heat current cannot occur in reciprocal systems, and can only arise in many-body systems in heat transfer. The use of nonreciprocity therefore points to a new regime of near-field heat transfer for the control of heat flow in the nanoscale.
View details for DOI 10.1103/PhysRevLett.117.134303
View details for Web of Science ID 000383852100004
View details for PubMedID 27715122
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Bloch oscillation and unidirectional translation of frequency in a dynamically modulated ring resonator
OPTICA
2016; 3 (9): 1014-1018
View details for DOI 10.1364/OPTICA.3.001014
View details for Web of Science ID 000387100100017
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Radiative human body cooling by nanoporous polyethylene textile
SCIENCE
2016; 353 (6303): 1019-1023
Abstract
Thermal management through personal heating and cooling is a strategy by which to expand indoor temperature setpoint range for large energy saving. We show that nanoporous polyethylene (nanoPE) is transparent to mid-infrared human body radiation but opaque to visible light because of the pore size distribution (50 to 1000 nanometers). We processed the material to develop a textile that promotes effective radiative cooling while still having sufficient air permeability, water-wicking rate, and mechanical strength for wearability. We developed a device to simulate skin temperature that shows temperatures 2.7° and 2.0°C lower when covered with nanoPE cloth and with processed nanoPE cloth, respectively, than when covered with cotton. Our processed nanoPE is an effective and scalable textile for personal thermal management.
View details for DOI 10.1126/science.aaf5471
View details for PubMedID 27701110
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Highly tunable refractive index visible-light metasurface from block copolymer self-assembly
NATURE COMMUNICATIONS
2016; 7
Abstract
The refractive index of natural transparent materials is limited to 2-3 throughout the visible wavelength range. Wider controllability of the refractive index is desired for novel optical applications such as nanoimaging and integrated photonics. We report that metamaterials consisting of period and symmetry-tunable self-assembled nanopatterns can provide a controllable refractive index medium for a broad wavelength range, including the visible region. Our approach exploits the independent control of permeability and permittivity with nanoscale objects smaller than the skin depth. The precise manipulation of the interobject distance in block copolymer nanopatterns via pattern shrinkage increased the effective refractive index up to 5.10. The effective refractive index remains above 3.0 over more than 1,000 nm wavelength bandwidth. Spatially graded and anisotropic refractive indices are also obtained with the design of transitional and rotational symmetry modification.
View details for DOI 10.1038/ncomms12911
View details for PubMedID 27683077
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Roadmap on optical metamaterials
JOURNAL OF OPTICS
2016; 18 (9)
View details for DOI 10.1088/2040-8978/18/9/093005
View details for Web of Science ID 000390221200005
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Plasmonic Circuit Theory for Multiresonant Light Funneling to a Single Spatial Hot Spot
NANO LETTERS
2016; 16 (9): 5764-5769
Abstract
We present a theoretical framework, based on plasmonic circuit models, for generating a multiresonant field intensity enhancement spectrum at a single "hot spot" in a plasmonic device. We introduce a circuit model, consisting of an array of coupled LC resonators, that directs current asymmetrically in the array, and we show that this circuit can funnel energy efficiently from each resonance to a single element. We implement the circuit model in a plasmonic nanostructure consisting of a series of metal bars of differing length, with nearest neighbor metal bars strongly coupled electromagnetically through air gaps. The resulting nanostructure resonantly traps different wavelengths of incident light in separate gap regions, yet it funnels the energy of different resonances to a common location, which is consistent with our circuit model. Our work is important for a number of applications of plasmonic nanoantennas in spectroscopy, such as in single-molecule fluorescence spectroscopy or Raman spectroscopy.
View details for DOI 10.1021/acs.nanolett.6b02474
View details for Web of Science ID 000383412100066
View details for PubMedID 27518827
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Slanted gold mushroom array: a switchable bi/tridirectional surface plasmon polariton splitter.
Nanoscale
2016; 8 (34): 15505-15513
Abstract
Surface plasmon polaritons (SPPs) show great promise in providing an ultracompact platform for integrated photonic circuits. However, challenges remain in easily and efficiently coupling light into and subsequently routing SPPs. Here, we theoretically propose and experimentally demonstrate a switchable bi/tridirectional beam splitter which can simultaneously perform both tasks. The photonic device consists of a periodic array of slanted gold 'mushrooms' composed of angled dielectric pillars with gold caps extruding from a periodic array of perforations in a gold film. The unidirectional coupling results from the interference of the in-plane guided modes scattered by a pair of dislocated gold gratings, while the output channel is determined by the polarization of the incident beam. This device, in combination with dynamic polarization modulation techniques, has the potential to serve as a router or switch in plasmonic integrated circuits.
View details for DOI 10.1039/c6nr03488h
View details for PubMedID 27523083
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Near-Field Enhanced Negative Luminescent Refrigeration
PHYSICAL REVIEW APPLIED
2016; 6 (2)
View details for DOI 10.1103/PhysRevApplied.6.024014
View details for Web of Science ID 000381610300003
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Hyperbolic Weyl Point in Reciprocal Chiral Metamaterials.
Physical review letters
2016; 117 (5): 057401-?
Abstract
We report the existence of Weyl points in a class of noncentral symmetric metamaterials, which has time reversal symmetry, but does not have inversion symmetry due to chiral coupling between electric and magnetic fields. This class of metamaterial exhibits either type-I or type-II Weyl points depending on its nonlocal response. We also provide a physical realization of such metamaterial consisting of an array of metal wires in the shape of elliptical helices which exhibits type-II Weyl points.
View details for DOI 10.1103/PhysRevLett.117.057401
View details for PubMedID 27517792
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High-Performance Ultrathin BiVO4 Photoanode on Textured Polydimethylsiloxane Substrates for Solar Water Splitting
ACS ENERGY LETTERS
2016; 1 (1): 68-75
View details for DOI 10.1021/acsenergylett.6b00032
View details for Web of Science ID 000389617700013
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Roadmap on optical energy conversion
JOURNAL OF OPTICS
2016; 18 (7)
View details for DOI 10.1088/2040-8978/18/7/073004
View details for Web of Science ID 000383908800007
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Near-field radiative heat transfer between parallel structures in the deep subwavelength regime
NATURE NANOTECHNOLOGY
2016; 11 (6): 515-?
Abstract
Thermal radiation between parallel objects separated by deep subwavelength distances and subject to large thermal gradients (>100 K) can reach very high magnitudes, while being concentrated on a narrow frequency distribution. These unique characteristics could enable breakthrough technologies for thermal transport control and electricity generation (for example, by radiating heat exactly at the bandgap frequency of a photovoltaic cell). However, thermal transport in this regime has never been achieved experimentally due to the difficulty of maintaining large thermal gradients over nanometre-scale distances while avoiding other heat transfer mechanisms, namely conduction. Here, we show near-field radiative heat transfer between parallel SiC nanobeams in the deep subwavelength regime. The distance between the beams is controlled by a high-precision micro-electromechanical system (MEMS). We exploit the mechanical stability of nanobeams under high tensile stress to minimize thermal buckling effects, therefore keeping control of the nanometre-scale separation even at large thermal gradients. We achieve an enhancement of heat transfer of almost two orders of magnitude with respect to the far-field limit (corresponding to a 42 nm separation) and show that we can maintain a temperature gradient of 260 K between the cold and hot surfaces at ∼100 nm distance.
View details for DOI 10.1038/NNANO.2016.20
View details for Web of Science ID 000377476800009
View details for PubMedID 26950243
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Exceptional Contours and Band Structure Design in Parity-Time Symmetric Photonic Crystals
PHYSICAL REVIEW LETTERS
2016; 116 (20)
Abstract
We investigate the properties of two-dimensional parity-time symmetric periodic systems whose non-Hermitian periodicity is an integer multiple of the underlying Hermitian system's periodicity. This creates a natural set of degeneracies that can undergo thresholdless PT transitions. We derive a k·p perturbation theory suited to the continuous eigenvalues of such systems in terms of the modes of the underlying Hermitian system. In photonic crystals, such thresholdless PT transitions are shown to yield significant control over the band structure of the system, and can result in all-angle supercollimation, a PT-superprism effect, and unidirectional behavior.
View details for DOI 10.1103/PhysRevLett.116.203902
View details for Web of Science ID 000376267300007
View details for PubMedID 27258869
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Thermal-to-electrical energy conversion by diodes under negative illumination
PHYSICAL REVIEW B
2016; 93 (16)
View details for DOI 10.1103/PhysRevB.93.161410
View details for Web of Science ID 000374950300003
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Broadband Absorption Enhancement in Solar Cells with an Atomically Thin Active Layer
ACS PHOTONICS
2016; 3 (4): 571-577
View details for DOI 10.1021/acsphotonics.5b00510
View details for Web of Science ID 000374811700013
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Angle-selective perfect absorption with two-dimensional materials
LIGHT-SCIENCE & APPLICATIONS
2016; 5
Abstract
Two-dimensional (2D) materials have great potential in photonic and optoelectronic devices. However, the relatively weak light absorption in 2D materials hinders their application in practical devices. Here, we propose a general approach to achieve angle-selective perfect light absorption in 2D materials. As a demonstration of the concept, we experimentally show giant light absorption by placing large-area single-layer graphene on a structure consisting of a chalcogenide layer atop a mirror and achieving a total absorption of 77.6% in the mid-infrared wavelength range (~13 μm), where the graphene contributes a record-high 47.2% absorptivity of mid-infrared light. Construction of such an angle-selective thin optical element is important for solar and thermal energy harvesting, photo-detection and sensing applications. Our study points to a new opportunity to combine 2D materials with photonic structures to enable novel device applications.
View details for DOI 10.1038/lsa.2016.52
View details for Web of Science ID 000374463100007
View details for PubMedCentralID PMC6059899
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Angle-selective perfect absorption with two-dimensional materials.
Light, science & applications
2016; 5 (3): e16052
Abstract
Two-dimensional (2D) materials have great potential in photonic and optoelectronic devices. However, the relatively weak light absorption in 2D materials hinders their application in practical devices. Here, we propose a general approach to achieve angle-selective perfect light absorption in 2D materials. As a demonstration of the concept, we experimentally show giant light absorption by placing large-area single-layer graphene on a structure consisting of a chalcogenide layer atop a mirror and achieving a total absorption of 77.6% in the mid-infrared wavelength range (~13 μm), where the graphene contributes a record-high 47.2% absorptivity of mid-infrared light. Construction of such an angle-selective thin optical element is important for solar and thermal energy harvesting, photo-detection and sensing applications. Our study points to a new opportunity to combine 2D materials with photonic structures to enable novel device applications.
View details for DOI 10.1038/lsa.2016.52
View details for PubMedID 30167153
View details for PubMedCentralID PMC6059899
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Controlling the electrostatic Coulomb interaction using metamaterials
PHYSICAL REVIEW B
2016; 93 (7)
View details for DOI 10.1103/PhysRevB.93.075433
View details for Web of Science ID 000370795400003
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Photonic gauge potential in a system with a synthetic frequency dimension
OPTICS LETTERS
2016; 41 (4): 741-744
Abstract
We generalize the concept of photonic gauge potential in real space by introducing an additional "synthetic" frequency dimension in addition to the real space dimensions. As an illustration, we consider a one-dimensional array of ring resonators, each supporting a set of resonant modes having a frequency comb with spacing Ω, and undergoing a refractive index modulation at the modulation frequency equal to Ω. We show that the modulation phase provides a gauge potential in the synthetic two-dimensional space with the dimensions being the frequency and the spatial axes. Such a gauge potential can create a topologically protected one-way edge state in the synthetic space that is useful for high-efficiency generation of higher-order side bands.
View details for DOI 10.1364/OL.41.000741
View details for Web of Science ID 000369942900022
View details for PubMedID 26872177
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Dynamic non-reciprocal meta-surfaces with arbitrary phase reconfigurability based on photonic transition in meta-atoms
APPLIED PHYSICS LETTERS
2016; 108 (2)
View details for DOI 10.1063/1.4939915
View details for Web of Science ID 000370258400009
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Passively Cooling Water below the Ambient Temperature during the Day Via Radiative Sky Cooling
AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS. 2016
View details for Web of Science ID 000444080400009
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Hyperbolic Weyl Point in Reciprocal Chiral Metamaterial
IEEE. 2016: 977
View details for Web of Science ID 000400013900345
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Photonic Structure Textile Design for Localized Thermal Management via Radiative Cooling
IEEE. 2016
View details for Web of Science ID 000391286400448
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Achieving the gauge potential for the photon in a synthetic space
IEEE. 2016
View details for Web of Science ID 000391286402192
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Nanophotonic Control of Heat: New Fundamental Effects and Applications
IEEE. 2016
View details for Web of Science ID 000391286400447
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Radiative cooling of solar absorbers using a transparent photonic crystal thermal blackbody
IEEE. 2016
View details for Web of Science ID 000391286400449
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Current-Voltage Enhancement of a Single Coaxial Nanowire Solar Cell
ACS PHOTONICS
2015; 2 (12): 1698-1704
View details for DOI 10.1021/acsphotonics.5b00236
View details for Web of Science ID 000366884600009
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Achieving nonreciprocal unidirectional single-photon quantum transport using the photonic Aharonov-Bohm effect
OPTICS LETTERS
2015; 40 (22): 5140-5143
Abstract
We show that nonreciprocal unidirectional single-photon quantum transport can be achieved with the photonic Aharonov-Bohm effect. The system consists of a 1D waveguide coupling to two three-level atoms of the V-type. The two atoms, in addition, are each driven by an external coherent field. We show that the phase of the external coherent field provides a gauge potential for the photon states. With a proper choice of the phase difference between the two coherent fields, the transport of a single photon can exhibit unity contrast in its transmissions for the two propagation directions.
View details for DOI 10.1364/OL.40.005140
View details for Web of Science ID 000366133400004
View details for PubMedID 26565819
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Topologically nontrivial Floquet band structure in a system undergoing photonic transitions in the ultrastrong-coupling regime
PHYSICAL REVIEW A
2015; 92 (5)
View details for DOI 10.1103/PhysRevA.92.053822
View details for Web of Science ID 000364396100017
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Unified picture of modal loss rates from microwave to optical frequencies in deep-subwavelength metallic structures: A case study with slot waveguides
APPLIED PHYSICS LETTERS
2015; 107 (17)
View details for DOI 10.1063/1.4934707
View details for Web of Science ID 000364234200002
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Photon management for enhanced open-circuit voltage in nanostructured solar cells
JOURNAL OF PHYSICS D-APPLIED PHYSICS
2015; 48 (41)
View details for DOI 10.1088/0022-3727/48/41/413001
View details for Web of Science ID 000362007100001
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Analytical treatment of near-field electromagnetic heat transfer at the nanoscale
PHYSICAL REVIEW B
2015; 92 (14)
View details for DOI 10.1103/PhysRevB.92.144307
View details for Web of Science ID 000362895200003
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Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2015; 112 (40): 12282-12287
Abstract
A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.
View details for DOI 10.1073/pnas.1509453112
View details for Web of Science ID 000363125400032
View details for PubMedID 26392542
View details for PubMedCentralID PMC4603484
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Suppressing sub-bandgap phonon-polariton heat transfer in near-field thermophotovoltaic devices for waste heat recovery
APPLIED PHYSICS LETTERS
2015; 107 (9)
View details for DOI 10.1063/1.4929949
View details for Web of Science ID 000360926200006
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Plasmonic coaxial waveguide-cavity devices
OPTICS EXPRESS
2015; 23 (16): 20549-20562
Abstract
We theoretically investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. The resonators are terminated either in a short or an open circuit. We show that the properties of these waveguide-cavity systems can be accurately described using a single-mode scattering matrix theory. We also show that, with proper choice of their design parameters, three-dimensional plasmonic coaxial waveguide-cavity devices and two-dimensional metal-dielectric-metal devices can have nearly identical transmission spectra. Thus, three-dimensional plasmonic coaxial waveguides offer a platform for practical implementation of two-dimensional metal-dielectric-metal device designs.
View details for DOI 10.1364/OE.23.020549
View details for Web of Science ID 000361036400031
View details for PubMedID 26367907
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Theory of Half-Space Light Absorption Enhancement for Leaky Mode Resonant Nanowires
NANO LETTERS
2015; 15 (8): 5513-5518
Abstract
Semiconductor nanowires supporting leaky mode resonances have been used to increase light absorption in optoelectronic applications from solar cell to photodetector and sensor. The light conventionally illuminates these devices with a wide range of different incident angles from half space. Currently, most of the investigated nanowires have centrosymmetric geometry cross section, such as circle, hexagon, and rectangle. Here we show that the absorption capability of these symmetrical nanowires has an upper limit under the half-space illumination. Based on the temporal coupled-mode equation, we develop a reciprocity theory for leaky mode resonances in order to connect the angle-dependent absorption cross section and the radiation pattern. We show that in order to exceed such a half-space limit the radiation pattern should be noncentrosymmetric and dominate in the direction reciprocal to the illumination. As an example, we design a metal trough structure to achieve the desired radiation pattern for an embedded nanowire. In comparison to a single nanowire case the trough structure indeed overcomes the half-space limit and leads to 39% and 64% absorption enhancement in TM and TE polarizations, respectively. Also the trough structure enables the enhancement over a broad wavelength range.
View details for DOI 10.1021/acs.nanolett.5b02044
View details for PubMedID 26171950
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Analog of superradiant emission in thermal emitters
PHYSICAL REVIEW B
2015; 92 (2)
View details for DOI 10.1103/PhysRevB.92.024302
View details for Web of Science ID 000357855900007
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Resonator-free realization of effective magnetic field for photons
NEW JOURNAL OF PHYSICS
2015; 17
View details for DOI 10.1088/1367-2630/17/7/075008
View details for Web of Science ID 000359128100005
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Optical-Electronic Analysis of the Intrinsic Behaviors of Nanostructured Ultrathin Crystalline Silicon Solar Cells
ACS PHOTONICS
2015; 2 (7): 883-889
View details for DOI 10.1021/acsphotonics.5b00081
View details for Web of Science ID 000358188300014
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Three-Dimensional Dynamic Localization of Light from a Time-Dependent Effective Gauge Field for Photons
PHYSICAL REVIEW LETTERS
2015; 114 (24)
Abstract
We introduce a method to achieve the three-dimensional dynamic localization of light. We consider a dynamically modulated resonator lattice that has been previously shown to exhibit an effective gauge potential for photons. When such an effective gauge potential varies sinusoidally in time, dynamic localization of light can be achieved. Moreover, while previous works on such an effective gauge potential for photons were carried out in the regime where the rotating wave approximation is valid, the effect of dynamic localization persists even when the counterrotating term is taken into count.
View details for DOI 10.1103/PhysRevLett.114.243901
View details for Web of Science ID 000356221000004
View details for PubMedID 26196977
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Limitations of nonlinear optical isolators due to dynamic reciprocity
NATURE PHOTONICS
2015; 9 (6): 388-392
View details for DOI 10.1038/NPHOTON.2015.79
View details for Web of Science ID 000355232400012
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Input-output formalism for few-photon transport: A systematic treatment beyond two photons
PHYSICAL REVIEW A
2015; 91 (4)
View details for DOI 10.1103/PhysRevA.91.043845
View details for Web of Science ID 000353680100025
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Heat-flux control and solid-state cooling by regulating chemical potential of photons in near-field electromagnetic heat transfer
PHYSICAL REVIEW B
2015; 91 (13)
View details for DOI 10.1103/PhysRevB.91.134301
View details for Web of Science ID 000352683900003
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Optical separation of heterogeneous size distributions of microparticles on silicon nitride strip waveguides
OPTICS EXPRESS
2015; 23 (7): 8855-8866
Abstract
We demonstrate two complementary optical separation techniques of dielectric particles on the surface of silicon nitride waveguides. Glass particles ranging from 2 μm to 10 μm in diameter are separated at guided powers below 40 mW. The effects of optical, viscous, and frictional forces on the particles are modeled and experimentally shown to enable separation. Particle interactions are investigated and shown to decrease measured particle velocity without interfering with the overall particle separation distribution. The demonstrated separation techniques have the potential to be integrated with microfluidic structures for cell sorting.
View details for DOI 10.1364/OE.23.008855
View details for Web of Science ID 000352290000088
View details for PubMedID 25968723
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Planar immersion lens with metasurfaces
PHYSICAL REVIEW B
2015; 91 (12)
View details for DOI 10.1103/PhysRevB.91.125145
View details for Web of Science ID 000352196700006
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Near-Field Radiative Heat Transfer between Integrated Nanostructures using Silicon Carbide
IEEE. 2015
View details for Web of Science ID 000370627100356
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Radiative cooling for solar cells
Conference on Physics, Simulation, and Photonic Engineering of Photovoltaic Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2015
View details for DOI 10.1117/12.2080148
View details for Web of Science ID 000353897400026
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Sufficient Condition for Perfect Antireflection by Optical Resonance at Dielectric Interface
Conference on Physics, Simulation, and Photonic Engineering of Photovoltaic Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2015
View details for DOI 10.1117/12.2076242
View details for Web of Science ID 000353897400002
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Light Guiding by Gauge Field for Photons
IEEE. 2015
View details for Web of Science ID 000370627100255
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Routing of deep-subwavelength optical beams without reflection and diffraction using infinitely anisotropic metamaterials
SPIE-INT SOC OPTICAL ENGINEERING. 2015
View details for DOI 10.1117/12.2081040
View details for Web of Science ID 000354276800015
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Condition for Perfect Resonant Antireflection in Solar Cells
IEEE. 2015
View details for Web of Science ID 000369992902113
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Theory and Practice of Resonant Antireflection
IEEE. 2015
View details for Web of Science ID 000370627102443
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Recent advances on non-reciprocal light manipulation from dynamic modulation
IEEE. 2015: 400–402
View details for Web of Science ID 000379127300134
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Using time-dependent effective gauge field for photons to achieve dynamic localization of light
SPIE-INT SOC OPTICAL ENGINEERING. 2015
View details for DOI 10.1117/12.2189528
View details for Web of Science ID 000365749100034
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Near complete violation of detailed balance in thermal radiation
IEEE. 2015
View details for Web of Science ID 000370627100358
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Condition for perfect antireflection by optical resonance at material interface
OPTICA
2014; 1 (6): 388-395
View details for DOI 10.1364/OPTICA.1.000388
View details for Web of Science ID 000354864400006
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Near-complete violation of detailed balance in thermal radiation
PHYSICAL REVIEW B
2014; 90 (22)
View details for DOI 10.1103/PhysRevB.90.220301
View details for Web of Science ID 000346388500002
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Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures
NANO LETTERS
2014; 14 (12): 6971-6975
Abstract
Near-field heat transfer recently attracted growing interest but was demonstrated experimentally only in macroscopic systems. However, several projected applications would be relevant mostly in integrated nanostructures. Here we demonstrate a platform for near-field heat transfer on-chip and show that it can be the dominant thermal transport mechanism between integrated nanostructures, overcoming background substrate conduction and the far-field limit (by factors 8 and 7, respectively). Our approach could enable the development of active thermal control devices such as thermal rectifiers and transistors.
View details for DOI 10.1021/nl503236k
View details for Web of Science ID 000346322800034
View details for PubMedID 25420115
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Passive radiative cooling below ambient air temperature under direct sunlight.
Nature
2014; 515 (7528): 540-544
Abstract
Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day.
View details for DOI 10.1038/nature13883
View details for PubMedID 25428501
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Accelerating simulation of ensembles of locally differing optical structures via a Schur complement domain decomposition
OPTICS LETTERS
2014; 39 (22): 6458-6461
Abstract
We present a Schur complement domain decomposition method that can significantly accelerate simulation of ensembles of locally differing optical structures. We apply the method to design a multi-spatial-mode photonic crystal waveguide splitter that exhibits high transmission and preservation of modal content, showing design acceleration by more than a factor of 20.
View details for DOI 10.1364/OL.39.006458
View details for Web of Science ID 000344986000026
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Approaching total absorption at near infrared in a large area monolayer graphene by critical coupling
APPLIED PHYSICS LETTERS
2014; 105 (18)
View details for DOI 10.1063/1.4901181
View details for Web of Science ID 000345000000005
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Consideration of enhancement of thermal rectification using metamaterial models
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2014; 148: 156-164
View details for DOI 10.1016/j.jqsrt.2014.07.007
View details for Web of Science ID 000342254100018
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Complete power concentration into a single waveguide in large-scale waveguide array lenses
SCIENTIFIC REPORTS
2014; 4
Abstract
Waveguide array lenses are waveguide arrays that focus light incident on all waveguides at the input side into a small number of waveguides at the output side. Ideal waveguide array lenses provide complete (100%) power concentration of incident light into a single waveguide. While of great interest for several applications, ideal waveguide array lenses have not been demonstrated for practical arrays with large numbers of waveguides. The only waveguide arrays that have sufficient degrees of freedom to allow for the design of an ideal waveguide array lens are those where both the propagation constants of the individual waveguides and the coupling constants between the waveguides vary as a function of space. Here, we use state-of-the-art numerical methods to demonstrate complete power transfer into a single waveguide for waveguide array lenses with large numbers of waveguides. We verify this capability for more than a thousand waveguides using a spatial coupled mode theory. We hereby extend the state-of-art by more than two orders of magnitude. We also demonstrate for the first time a physical design for an ideal waveguide array lens. The design is based on an aperiodic metallic waveguide array and focuses ~100% of the incident light into a deep-subwavelength focal spot.
View details for DOI 10.1038/srep06635
View details for Web of Science ID 000343089300005
View details for PubMedID 25319203
View details for PubMedCentralID PMC4198864
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Graphene surface plasmons at the near-infrared optical regime
SCIENTIFIC REPORTS
2014; 4
Abstract
Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back electrical gating and chemical doping methods cannot facilitate the demonstration of graphene SPs at the near-infrared (NIR) window because of the limited shift of the Fermi level. Here, we present the evidence for the existence of graphene SPs on a tapered graphene-silicon waveguide tip at a NIR wavelength, employing a surface carrier transfer method with molybdenum trioxides. The coupling between the graphene surface plasmons and the guiding mode in silicon waveguides allows for the observation of the concentrated field of the SPs in the tip by near-field scanning optical microscopy. Thus the hot spot from the concentrated SPs in the graphene layer can be used as a key experimental signature of graphene SPs. The NIR graphene SPs opens a new perspective for optical communications, optical sensing and imaging, and optical data storage with extreme spatial confinement, broad bandwidth and high tunability.
View details for DOI 10.1038/srep06559
View details for Web of Science ID 000343060300006
View details for PubMedID 25297570
View details for PubMedCentralID PMC4190570
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Two-dimensional Green's tensor for gyrotropic clusters composed of circular cylinders
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
2014; 31 (10): 2294-2303
Abstract
The construction of Green's tensor for two-dimensional gyrotropic photonic clusters composed of cylinders with circular cross sections using the semi-analytic multipole method is presented. The high efficiency and accuracy of the method is demonstrated. The developed method is applied to gyrotropic clusters that support topological chiral Hall edge states. The remarkable tolerance of chiral Hall edge modes toward substantial cluster separation is revealed. The transformation of chiral Hall edge states as the cluster separation increases is also presented. The excitation of chiral Hall edge modes for different source orientations is considered. Both gyroelectric and gyromagnetic (ferrite) clusters are treated.
View details for DOI 10.1364/JOSAA.31.002294
View details for Web of Science ID 000344781600026
View details for PubMedID 25401258
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Non-reciprocal phase shift induced by an effective magnetic flux for light
NATURE PHOTONICS
2014; 8 (9): 701-705
View details for DOI 10.1038/NPHOTON.2014.177
View details for Web of Science ID 000342600100012
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Light Guiding by Effective Gauge Field for Photons
PHYSICAL REVIEW X
2014; 4 (3)
View details for DOI 10.1103/PhysRevX.4.031031
View details for Web of Science ID 000341248700001
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Directional perfect absorption using deep subwavelength low-permittivity films
PHYSICAL REVIEW B
2014; 90 (8)
View details for DOI 10.1103/PhysRevB.90.085411
View details for Web of Science ID 000341164000010
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Light trapping in photonic crystals
ENERGY & ENVIRONMENTAL SCIENCE
2014; 7 (8): 2725-2738
View details for DOI 10.1039/c4ee00839a
View details for Web of Science ID 000339861800029
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Radiative cooling of solar cells
OPTICA
2014; 1 (1): 32-38
View details for DOI 10.1364/OPTICA.1.000032
View details for Web of Science ID 000354862800007
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Spectral light separator based on deep-subwavelength resonant apertures in a metallic film
APPLIED PHYSICS LETTERS
2014; 105 (1)
View details for DOI 10.1063/1.4887059
View details for Web of Science ID 000339664900014
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Dislocated Double-Layer Metal Gratings: An Efficient Unidirectional Coupler
NANO LETTERS
2014; 14 (7): 3848-3854
Abstract
We propose theoretically and demonstrate experimentally a dislocated double-layer metal grating structure, which operates as a unidirectional coupler capable of launching surface plasmon polaritons in a desired direction under normal illumination. The structure consists of a slanted dielectric grating sandwiched between two gold gratings. The upper gold grating has a nonzero lateral relative displacement with respect to the lower one. Numerical simulations show that a grating structure with 7 periods can convert 49% of normally incident light into surface plasmons with a contrast ratio of 78 between the powers of the surface plasmons launched in two opposite directions. We explain the unidirectional coupling phenomenon by the dislocation-induced interference of the diffracted waves from the upper and lower gold gratings. Furthermore, we developed a simple and cost-effective technique to fabricate the structure via tilted two-beam interference lithography and subsequent shadow deposition of gold. The experimental results demonstrate a coupling efficiency of 36% and a contrast ratio of 43. The relatively simple periodic nature of our structure lends itself to large-scale low-cost fabrication and simple theoretical analysis. Also, unlike the previous unidirectional couplers based on aperiodic structures, the design parameters of our unidirectional coupler can be determined analytically. Therefore, this structure can be an important component for surface-plasmon-based nanophotonic circuits by providing an efficient interface between free-space and surface plasmon waves.
View details for DOI 10.1021/nl501007d
View details for Web of Science ID 000338979700023
View details for PubMedID 24926990
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Total absorption by degenerate critical coupling
APPLIED PHYSICS LETTERS
2014; 104 (25)
View details for DOI 10.1063/1.4885517
View details for Web of Science ID 000338515900010
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Spatial control of surface plasmon polariton excitation at planar metal surface
OPTICS LETTERS
2014; 39 (12): 3587-3590
Abstract
We illustrate that the surface plasmon polariton (SPP) excitation through the prism coupling method is fundamentally limited by destructive interference of spatial light components. We propose that the destructive interference can be canceled out by tailoring the relative phase for the different wave-vector components. As a numerical demonstration, we show that through the phase modulation the excited SPP field is concentrated to a hot energy spot, and the SPP field intensity is dramatically enhanced about three-fold in comparison with a conventional Gaussian beam illumination. The proposed phase-shaped beam approach provides a new degree of freedom to fundamentally control the SPP excitation and benefits the development of surface-enhanced applications.
View details for DOI 10.1364/OL.39.003587
View details for Web of Science ID 000338870500058
View details for PubMedID 24978543
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Sensitivity analysis and optimization of sub-wavelength optical gratings using adjoints
OPTICS EXPRESS
2014; 22 (11): 12971-12981
Abstract
Numerical optimization of photonic devices is often limited by a large design space the finite-differences gradient method requires as many electric field computations as there are design parameters. Adjoint-based optimization can deliver the same gradients with only two electric field computations. Here, we derive the relevant adjoint formalism and illustrate its application for a waveguide slab, and for the design of optical sub-wavelength gratings.
View details for DOI 10.1364/OE.22.012971
View details for Web of Science ID 000337501600027
View details for PubMedID 24921494
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Optical impedance transformer for transparent conducting electrodes.
Nano letters
2014; 14 (5): 2755-2758
Abstract
A fundamental limitation of transparent conducting electrode design is thought to be the trade-off between photonic and electronic performances. The photonic transmission property of a transparent conducting electrode, however, is not intrinsic but depends critically on the electromagnetic environment where the electrode is located. We develop the concept of optical impedance transformation, and use this concept to design nanophotonic structures that provide broadband and omnidirectional reduction of optical loss in an ultrathin transparent conducting electrode, without compromising its electrical performance.
View details for DOI 10.1021/nl500741f
View details for PubMedID 24773302
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Optical Fano resonance of an individual semiconductor nanostructure
NATURE MATERIALS
2014; 13 (5): 471-475
Abstract
Fano resonances with a characteristic asymmetric line shape can be observed in light scattering, transmission and reflection spectra of resonant optical systems. They result from interference between direct and indirect, resonance-assisted pathways. In the nanophotonics field, Fano effects have been observed in a wide variety of systems, including metallic nanoparticle assemblies, metamaterials and photonic crystals. Their unique properties find extensive use in applications, including optical filtering, polarization selectors, sensing, lasers, modulators and nonlinear optics. We report on the observation of a Fano resonance in a single semiconductor nanostructure, opening up opportunities for their use in active photonic devices. We also show that Fano-resonant semiconductor nanostructures afford the intriguing opportunity to simultaneously measure the far-field scattering response and the near-field energy storage by extracting photogenerated charge. Together they can provide a complete experimental characterization of this type of resonance.
View details for DOI 10.1038/NMAT3927
View details for Web of Science ID 000334845600017
View details for PubMedID 24747781
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Parity-time-symmetric whispering-gallery microcavities
NATURE PHYSICS
2014; 10 (5): 394-398
View details for DOI 10.1038/NPHYS2927
View details for Web of Science ID 000335371200019
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Light management for photovoltaics using high-index nanostructures
NATURE MATERIALS
2014; 13 (5): 451-460
Abstract
High-performance photovoltaic cells use semiconductors to convert sunlight into clean electrical power, and transparent dielectrics or conductive oxides as antireflection coatings. A common feature of these materials is their high refractive index. Whereas high-index materials in a planar form tend to produce a strong, undesired reflection of sunlight, high-index nanostructures afford new ways to manipulate light at a subwavelength scale. For example, nanoscale wires, particles and voids support strong optical resonances that can enhance and effectively control light absorption and scattering processes. As such, they provide ideal building blocks for novel, broadband antireflection coatings, light-trapping layers and super-absorbing films. This Review discusses some of the recent developments in the design and implementation of such photonic elements in thin-film photovoltaic cells.
View details for DOI 10.1038/NMAT3921
View details for Web of Science ID 000334845600014
View details for PubMedID 24751773
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Total Absorption in a Graphene Mono layer in the Optical Regime by Critical Coupling with a Photonic Crystal Guided Resonance
ACS PHOTONICS
2014; 1 (4): 347-353
View details for DOI 10.1021/ph400090p
View details for Web of Science ID 000335805200008
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Nanoscale thermal transport. II. 2003-2012
APPLIED PHYSICS REVIEWS
2014; 1 (1)
View details for DOI 10.1063/1.4832615
View details for Web of Science ID 000334098500010
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Energy efficient nanophotonics: Engineered light-matter interaction in sub-wavelength structures
OPTICS COMMUNICATIONS
2014; 314: 1-2
View details for DOI 10.1016/j.optcom.2013.10.002
View details for Web of Science ID 000329018800001
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Nearly Total Solar Absorption in Ultrathin Nanostructured Iron Oxide for Efficient Photoelectrochemical Water Splitting
ACS PHOTONICS
2014; 1 (3): 235-240
View details for DOI 10.1021/ph4001026
View details for Web of Science ID 000335802900013
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Detailed balance analysis and enhancement of open-circuit voltage in single-nanowire solar cells.
Nano letters
2014; 14 (2): 1011-1015
Abstract
We present a detailed balance analysis of current density-voltage modeling of a single-nanowire solar cell. Our analysis takes into account intrinsic material nonidealities in order to determine the theoretical efficiency limit of the single-nanowire solar cell. The analysis only requires the nanowire's absorption cross-section over all angles, which can be readily calculated analytically. We show that the behavior of both the current and voltage is due to coherent effects that arise from resonances of the nanowire. In addition, we elucidate the physics of open-circuit voltage enhancement over bulk cells in nanowires, by showing that the enhancement is related to the removal of resonances in the immediate spectral vicinity above the bandgap.
View details for DOI 10.1021/nl404501w
View details for PubMedID 24479660
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Fluctuational electrodynamics calculations of near-field heat transfer in non-planar geometries: A brief overview
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2014; 132: 3-11
View details for DOI 10.1016/j.jqsrt.2013.04.017
View details for Web of Science ID 000328174000002
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Large-scale ideal waveguide lenses with complete power concentration in a single waveguide
IEEE. 2014
View details for Web of Science ID 000369908601114
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Optical Impedance Transformer for Transparent Conducting Electrodes
Carbon Nanotubes, Graphene,and Associated Devices VII
SPIE-INT SOC OPTICAL ENGINEERING. 2014
View details for DOI 10.1117/12.2061159
View details for Web of Science ID 000343860300002
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Color-preserving daytime radiative cooling
IEEE. 2014
View details for Web of Science ID 000369908600434
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Demonstration of Strong Near-Field Radiative Heat Transfer between Nanostructures
IEEE. 2014
View details for Web of Science ID 000369908600454
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Parity-time (PT)-symmetric optical microcavities
IEEE. 2014
View details for Web of Science ID 000369908601266
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Observation of an effective magnetic field for light
IEEE. 2014
View details for Web of Science ID 000369908603195
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Nanophotonic Light Trapping Theory for Photovoltaics
NANOFABRICATION AND ITS APPLICATION IN RENEWABLE ENERGY
2014: 31-61
View details for Web of Science ID 000387104500003
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Optical Impedance Transformer for Transparent Conducting Electrodes
IEEE. 2014: 542–43
View details for Web of Science ID 000372323200258
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Photovoltaics: an alternative 'Sun' for solar cells.
Nature nanotechnology
2014; 9 (2): 92–93
View details for PubMedID 24496275
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Towards ultra-thin plasmonic silicon wafer solar cells with minimized efficiency loss.
Scientific reports
2014; 4: 4939
Abstract
The cost-effectiveness of market-dominating silicon wafer solar cells plays a key role in determining the competiveness of solar energy with other exhaustible energy sources. Reducing the silicon wafer thickness at a minimized efficiency loss represents a mainstream trend in increasing the cost-effectiveness of wafer-based solar cells. In this paper we demonstrate that, using the advanced light trapping strategy with a properly designed nanoparticle architecture, the wafer thickness can be dramatically reduced to only around 1/10 of the current thickness (180 μm) without any solar cell efficiency loss at 18.2%. Nanoparticle integrated ultra-thin solar cells with only 3% of the current wafer thickness can potentially achieve 15.3% efficiency combining the absorption enhancement with the benefit of thinner wafer induced open circuit voltage increase. This represents a 97% material saving with only 15% relative efficiency loss. These results demonstrate the feasibility and prospect of achieving high-efficiency ultra-thin silicon wafer cells with plasmonic light trapping.
View details for PubMedID 24820403
View details for PubMedCentralID PMC4018607
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Photonic Aharonov-Bohm effect in photon-phonon interactions
NATURE COMMUNICATIONS
2014; 5
Abstract
The Aharonov-Bohm effect is one of the most intriguing phenomena in both classical and quantum physics, and associates with a number of important and fundamental issues in quantum mechanics. The Aharonov-Bohm effects of charged particles have been experimentally demonstrated and found applications in various fields. Recently, attention has also focused on the Aharonov-Bohm effect for neutral particles, such as photons. Here we propose to utilize the photon-phonon interactions to demonstrate that photonic Aharonov-Bohm effects do exist for photons. By introducing nonreciprocal phases for photons, we observe experimentally a gauge potential for photons in the visible range based on the photon-phonon interactions in acousto-optic crystals, and demonstrate the photonic Aharonov-Bohm effect. The results presented here point to new possibilities to control and manipulate photons by designing an effective gauge potential.
View details for DOI 10.1038/ncomms4225
View details for Web of Science ID 000331141700001
View details for PubMedID 24476790
View details for PubMedCentralID PMC3916835
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Progress in 2D photonic crystal Fano resonance photonics
PROGRESS IN QUANTUM ELECTRONICS
2014; 38 (1): 1-74
View details for DOI 10.1016/j.pquantelec.2014.01.001
View details for Web of Science ID 000336348500001
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Light Trapping in Photonic Crystals
Conference on Thin Films for Solar and Energy Technology VI
SPIE-INT SOC OPTICAL ENGINEERING. 2014
View details for DOI 10.1117/12.2061160
View details for Web of Science ID 000349362600014
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Ultrahigh contrast and large-bandwidth thermal rectification in near-field electromagnetic thermal transfer between nanoparticles
Conference on Nanophotonic Materials XI
SPIE-INT SOC OPTICAL ENGINEERING. 2014
View details for DOI 10.1117/12.2061262
View details for Web of Science ID 000344107800012
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Efficiency above the Shockley-Queisser Limit by Using Nanophotonic Effects To Create Multiple Effective Bandgaps With a Single Semiconductor
NANO LETTERS
2014; 14 (1): 66-70
Abstract
We present a pure photonic approach to overcome the Shockley-Queisser limit. A single material can show different effective bandgap, set by its absorption spectrum, which depends on its photonic structure. In a tandem cell configuration constructed from a single material, one can achieve two different effective bandgaps, thereby exceeding the Shockley-Queisser limit.
View details for DOI 10.1021/nl403653j
View details for Web of Science ID 000329586700011
View details for PubMedID 24279726
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Two-dimensional chalcogenide nanoplates as tunable metamaterials via chemical intercalation.
Nano letters
2013; 13 (12): 5913-5918
Abstract
New plasmonic materials with tunable properties are in great need for nanophotonics and metamaterials applications. Here we present two-dimensional layered, metal chalcogenides as tunable metamaterials that feature both dielectric photonic and plasmonic modes across a wide spectral range from the infrared to ultraviolet. The anisotropic layered structure allows intercalation of organic molecules and metal atoms at the van der Waals gap of the host chalcogenide, presenting a chemical route to create heterostructures with molecular and atomic precision for photonic and plasmonic applications. This marks a departure from a lithographic method to create metamaterials. Monochromated electron energy-loss spectroscopy in a scanning transmission electron microscope was used to first establish the presence of the dielectric photonic and plasmonic modes in M2E3 (M = Bi, Sb; E = Se, Te) nanoplates and to observe marked changes in these modes after chemical intercalation. We show that these modal properties can also be tuned effectively by more conventional methods such as thickness control and alloy composition of the nanoplates.
View details for DOI 10.1021/nl402937g
View details for PubMedID 24266743
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Coupled double-layer Fano resonance photonic crystal filters with lattice-displacement
APPLIED PHYSICS LETTERS
2013; 103 (24)
View details for DOI 10.1063/1.4846475
View details for Web of Science ID 000328706500006
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Deep subwavelength plasmonic waveguide switch in double graphene layer structure
APPLIED PHYSICS LETTERS
2013; 103 (23)
View details for DOI 10.1063/1.4839420
View details for Web of Science ID 000328634900075
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Metamaterial band theory: fundamentals & applications
SCIENCE CHINA-INFORMATION SCIENCES
2013; 56 (12)
View details for DOI 10.1007/s11432-013-5039-7
View details for Web of Science ID 000328295500002
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Two-Dimensional Chalcogenide Nanoplates as Tunable Metamaterials via Chemical Intercalation
NANO LETTERS
2013; 13 (12): 5913-5918
Abstract
New plasmonic materials with tunable properties are in great need for nanophotonics and metamaterials applications. Here we present two-dimensional layered, metal chalcogenides as tunable metamaterials that feature both dielectric photonic and plasmonic modes across a wide spectral range from the infrared to ultraviolet. The anisotropic layered structure allows intercalation of organic molecules and metal atoms at the van der Waals gap of the host chalcogenide, presenting a chemical route to create heterostructures with molecular and atomic precision for photonic and plasmonic applications. This marks a departure from a lithographic method to create metamaterials. Monochromated electron energy-loss spectroscopy in a scanning transmission electron microscope was used to first establish the presence of the dielectric photonic and plasmonic modes in M2E3 (M = Bi, Sb; E = Se, Te) nanoplates and to observe marked changes in these modes after chemical intercalation. We show that these modal properties can also be tuned effectively by more conventional methods such as thickness control and alloy composition of the nanoplates.
View details for DOI 10.1021/nl402937g
View details for Web of Science ID 000328439200024
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Analytic properties of two-photon scattering matrix in integrated quantum systems determined by the cluster decomposition principle.
Physical review letters
2013; 111 (22): 223602-?
Abstract
We consider a general class of integrated quantum systems where photon-photon interaction occurs in a quantum device that is localized in space. Using techniques that are closely related to cluster decomposition principles in quantum field theory, we provide a general constraint on the analytic properties of a two-photon S matrix in this class of systems. We also show that the photon-photon interaction in these systems inevitably leads to frequency mixing and entanglement and that frequencies of the single photons cannot be preserved in these systems.
View details for PubMedID 24329447
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Analytic Properties of Two-Photon Scattering Matrix in Integrated Quantum Systems Determined by the Cluster Decomposition Principle
PHYSICAL REVIEW LETTERS
2013; 111 (22)
Abstract
We consider a general class of integrated quantum systems where photon-photon interaction occurs in a quantum device that is localized in space. Using techniques that are closely related to cluster decomposition principles in quantum field theory, we provide a general constraint on the analytic properties of a two-photon S matrix in this class of systems. We also show that the photon-photon interaction in these systems inevitably leads to frequency mixing and entanglement and that frequencies of the single photons cannot be preserved in these systems.
View details for DOI 10.1103/PhysRevLett.111.223602
View details for Web of Science ID 000327941100011
View details for PubMedID 24329447
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Color-preserving daytime radiative cooling
APPLIED PHYSICS LETTERS
2013; 103 (22)
View details for DOI 10.1063/1.4835995
View details for Web of Science ID 000327696300079
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Controlling the Flow of Light Using the Inhomogeneous Effective Gauge Field that Emerges from Dynamic Modulation
PHYSICAL REVIEW LETTERS
2013; 111 (20)
Abstract
We show that the effective gauge field for photons provides a versatile platform for controlling the flow of light. As an example we consider a photonic resonator lattice where the coupling strength between nearest neighbor resonators are harmonically modulated. By choosing different spatial distributions of the modulation phases, and hence imposing different inhomogeneous effective magnetic field configurations, we numerically demonstrate a wide variety of propagation effects including negative refraction, one-way mirror, and on- and off-axis focusing. Since the effective gauge field is imposed dynamically after a structure is constructed, our work points to the importance of the temporal degree of freedom for controlling the spatial flow of light.
View details for DOI 10.1103/PhysRevLett.111.203901
View details for Web of Science ID 000327243300002
View details for PubMedID 24289686
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Ultrahigh-contrast and large-bandwidth thermal rectification in near-field electromagnetic thermal transfer between nanoparticles
PHYSICAL REVIEW B
2013; 88 (18)
View details for DOI 10.1103/PhysRevB.88.184301
View details for Web of Science ID 000326507400002
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Effective magnetic field for photons based on the magneto-optical effect
PHYSICAL REVIEW A
2013; 88 (4)
View details for DOI 10.1103/PhysRevA.88.043847
View details for Web of Science ID 000326389100015
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A lateral optical equilibrium in waveguide-resonator optical force
OPTICS EXPRESS
2013; 21 (21): 25257-25270
Abstract
We consider the lateral optical force between a resonator and a waveguide, and study the possibility of an equilibrium that occurs solely from the optical force in such system. We prove analytically that a single-resonance system cannot give such an equilibrium in the resonator-waveguide force. We then show that two-resonance systems can provide such an equilibrium. We provide an intuitive way to predict the existence of an equilibrium, and give numerical examples.
View details for DOI 10.1364/OE.21.025257
View details for Web of Science ID 000326085600080
View details for PubMedID 24150366
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Double-layer Fano resonance photonic crystal filters
OPTICS EXPRESS
2013; 21 (21): 24582-24589
Abstract
We report ultra-compact surface-normal high-Q optical filters based on single- and double-layer stacked Fano resonance photonic crystal slabs on both Si and quartz substrates. A single layer photonic crystal filter was designed and a Q factor of 1,737 was obtained with 23 dB extinction ratio. With stacked double-layer photonic crystal configuration, the optical filter Q can increase to over 10,000,000 in design. Double-layer filters with quality factor of 9,734 and extinction ratio of 8 dB were experimentally demonstrated, for a filter design with target Q of 22,000.
View details for DOI 10.1364/OE.21.024582
View details for Web of Science ID 000326085600016
View details for PubMedID 24150302
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Broadband Sharp 90-degree Bends and T-Splitters in Plasmonic Coaxial Waveguides.
Nano letters
2013; 13 (10): 4753-4758
Abstract
We demonstrate numerically that sharp 90° bends and T-splitters can be designed in plasmonic coaxial waveguides at deep-subwavelength scale to operate without reflection and radiation over a broad range of wavelengths, including the telecommunication wavelength of 1.55 μm. We explain the principles of the operation using a transmission line model of the waveguide in the quasi-static limit. The compact bends and T-splitters open up a new avenue for the design of densely integrated optical circuits with minimal crosstalk.
View details for DOI 10.1021/nl402335x
View details for PubMedID 23981038
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Dissipation in few-photon waveguide transport [Invited]
PHOTONICS RESEARCH
2013; 1 (3): 110-114
View details for DOI 10.1364/PRJ.1.000110
View details for Web of Science ID 000209372500002
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Three-dimensional self-assembled photonic crystals with high temperature stability for thermal emission modification
NATURE COMMUNICATIONS
2013; 4
Abstract
Selective thermal emission in a useful range of energies from a material operating at high temperatures is required for effective solar thermophotovoltaic energy conversion. Three-dimensional metallic photonic crystals can exhibit spectral emissivity that is modified compared with the emissivity of unstructured metals, resulting in an emission spectrum useful for solar thermophotovoltaics. However, retention of the three-dimensional mesostructure at high temperatures remains a significant challenge. Here we utilize self-assembled templates to fabricate high-quality tungsten photonic crystals that demonstrate unprecedented thermal stability up to at least 1,400 °C and modified thermal emission at solar thermophotovoltaic operating temperatures. We also obtain comparable thermal and optical results using a photonic crystal comprising a previously unstudied material, hafnium diboride, suggesting that refractory metallic ceramic materials are viable candidates for photonic crystal-based solar thermophotovoltaic devices and should be more extensively studied.
View details for DOI 10.1038/ncomms3630
View details for Web of Science ID 000326472200019
View details for PubMedID 24129680
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Accelerated solution of the frequency-domain Maxwell's equations by engineering the eigenvalue distribution of the operator
OPTICS EXPRESS
2013; 21 (19): 22578-22595
Abstract
We introduce a simple method to accelerate the convergence of iterative solvers of the frequency-domain Maxwell's equations for deep-subwavelength structures. Using the continuity equation, the method eliminates the high multiplicity of near-zero eigenvalues of the operator while leaving the operator nearly positive-definite. The impact of the modified eigenvalue distribution on the accelerated convergence is explained by visualizing residual vectors and residual polynomials.
View details for DOI 10.1364/OE.21.022578
View details for Web of Science ID 000325547200082
View details for PubMedID 24104147
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Large-area free-standing ultrathin single-crystal silicon as processable materials.
Nano letters
2013; 13 (9): 4393-4398
Abstract
Silicon has been driving the great success of semiconductor industry, and emerging forms of silicon have generated new opportunities in electronics, biotechnology, and energy applications. Here we demonstrate large-area free-standing ultrathin single-crystalline Si at the wafer scale as new Si materials with processability. We fabricated them by KOH etching of the Si wafer and show their uniform thickness from 10 to sub-2 μm. These ultrathin Si exhibits excellent mechanical flexibility and bendability more than those with 20-30 μm thickness in previous study. Unexpectedly, these ultrathin Si materials can be cut with scissors like a piece of paper, and they are robust during various regular fabrication processings including tweezer handling, spin coating, patterning, doping, wet and dry etching, annealing, and metal deposition. We demonstrate the fabrication of planar and double-sided nanocone solar cells and highlight that the processability on both sides of surface together with the interesting property of these free-standing ultrathin Si materials opens up exciting opportunities to generate novel functional devices different from the existing approaches.
View details for DOI 10.1021/nl402230v
View details for PubMedID 23876030
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Optical pulling force and conveyor belt effect in resonator-waveguide system
OPTICS LETTERS
2013; 38 (17): 3264-3267
Abstract
We present the theoretical condition and actual numerical design that achieves an optical pulling force in resonator-waveguide systems, where the direction of the force on the resonator is in the opposite direction to the input light in the waveguide. We also show that this pulling force can occur in conjunction with the lateral optical equilibrium effect, such that the resonator is maintained at the fixed distance from the waveguide while experiencing the pulling force.
View details for DOI 10.1364/OL.38.003264
View details for Web of Science ID 000323758000019
View details for PubMedID 23988930
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What is - and what is not - an optical isolator
NATURE PHOTONICS
2013; 7 (8): 579-582
View details for DOI 10.1038/nphoton.2013.185
View details for Web of Science ID 000322450200002
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Photonic de Haas-van Alphen effect
OPTICS EXPRESS
2013; 21 (15): 18216-18224
Abstract
Based on the recently proposed concept of effective gauge potential and magnetic field for photons, we numerically demonstrate a photonic de Haas-van Alphen effect. We show that in a dynamically modulated photonic resonator lattice exhibiting an effect magnetic field, the trajectories of the light beam at a given frequency have the same shape as the constant energy contour for the photonic band structure of the lattice in the absence of the effective magnetic field.
View details for DOI 10.1364/OE.21.018216
View details for Web of Science ID 000322366300081
View details for PubMedID 23938692
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Modeling Coherent Backscattering Errors in Fiber Optic Gyroscopes for Sources of Arbitrary Line Width
JOURNAL OF LIGHTWAVE TECHNOLOGY
2013; 31 (13): 2070-2078
View details for DOI 10.1109/JLT.2013.2261283
View details for Web of Science ID 000319682100002
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Experimental Observation of Low Noise and Low Drift in a Laser-Driven Fiber Optic Gyroscope
JOURNAL OF LIGHTWAVE TECHNOLOGY
2013; 31 (13): 2079-2085
View details for DOI 10.1109/JLT.2013.2261285
View details for Web of Science ID 000319682100003
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Slow-Light Fiber-Bragg-Grating Strain Sensor With a 280-femtostrain/root Hz Resolution
JOURNAL OF LIGHTWAVE TECHNOLOGY
2013; 31 (11): 1804-1808
View details for DOI 10.1109/JLT.2013.2258658
View details for Web of Science ID 000318702800002
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Wireless power transfer in the presence of metallic plates: Experimental results
AIP ADVANCES
2013; 3 (6)
View details for DOI 10.1063/1.4809665
View details for Web of Science ID 000321144300002
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A transparent electrode based on a metal nanotrough network.
Nature nanotechnology
2013; 8 (6): 421-425
Abstract
Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide-the prototypical transparent electrode material-demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10Ω □(-1) at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ∼2Ω □(-1) at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.
View details for DOI 10.1038/nnano.2013.84
View details for PubMedID 23685985
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Near-infrared surface plasmon polariton dispersion control with hyperbolic metamaterials
OPTICS EXPRESS
2013; 21 (9): 11107-11114
Abstract
We demonstrate experimentally signatures and dispersion control of surface plasmon polaritons from 1 to 1.8 µm using periodic multilayer metallo-dielectric hyperbolic metamaterials. The fabricated structures are comprised of smooth films with very low metal filling factor. The measured dispersion properties of these hyperbolic metamaterials agree well with calculations using transfer matrix, finite-difference time-domain, and effective medium approximation methods despite using only 2.5 periods. The enhancement factor in the local photonic density of states from the studied samples in the near-infrared wavelength region is determined to be 2.5-3.5. Development of this type of metamaterial is relevant to sub-wavelength imaging, spontaneous emission and thermophotovoltaic applications.
View details for DOI 10.1364/OE.21.011107
View details for Web of Science ID 000318906500099
View details for PubMedID 23669967
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Upper bound on the modal material loss rate in plasmonic and metamaterial systems.
Physical review letters
2013; 110 (18): 183901-?
Abstract
A better understanding of optical loss in plasmonic and metamaterial systems is of increasing importance for both basic and applied research in a broad range of topics including sensors, antennas, optical interconnects, and photovoltaics. In this Letter, we use a photonic band formalism for plasmonics to exactly derive a fundamental upper bound on the nonradiative material loss rate of modes in plasmonic, polaritonic, and metamaterial systems. This bound is purely defined by material properties and cannot be overcome by device design. Moreover it is frequency dependent in the presence of multiple Lorentz poles. We numerically verify this bound through direct calculations for a range of plasmonic systems, including optical antennas where the bound places fundamental performance constraints.
View details for PubMedID 23683195
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Resonant cavity enhanced light harvesting in flexible thin-film organic solar cells
OPTICS LETTERS
2013; 38 (9): 1431-1433
Abstract
Dielectric/metal/dielectric (DMD) electrodes have the potential to significantly increase the absorption efficiency and photocurrent in flexible organic solar cells. We demonstrate that this enhancement is attributed to a broadband cavity resonance. Silver-based semitransparent DMD electrodes with sheet resistances below 10 ohm/sq. are fabricated on flexible polyethylene terephthalate (PET) substrates in a high-throughput roll-to-roll sputtering tool. We carefully study the effect of the semitransparent DMD electrode (here composed of Zn(x)Sn(y)O(z)/Ag/In(x)Sn(y)O(z)) on the optical device performance of a copper phthalocyanine (CuPc)/fullerene (C60) bilayer cell and illustrate that a resonant cavity enhanced light trapping effect dominates the optical behavior of the device.
View details for DOI 10.1364/OL.38.001431
View details for Web of Science ID 000318425600024
View details for PubMedID 23632508
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Modal Source Radiator Model for Arbitrary Two-Dimensional Arrays of Subwavelength Apertures on Metal Films
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2013; 19 (3)
View details for DOI 10.1109/JSTQE.2012.2229383
View details for Web of Science ID 000322125100012
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Upper Bound on the Modal Material Loss Rate in Plasmonic and Metamaterial Systems
PHYSICAL REVIEW LETTERS
2013; 110 (18)
Abstract
A better understanding of optical loss in plasmonic and metamaterial systems is of increasing importance for both basic and applied research in a broad range of topics including sensors, antennas, optical interconnects, and photovoltaics. In this Letter, we use a photonic band formalism for plasmonics to exactly derive a fundamental upper bound on the nonradiative material loss rate of modes in plasmonic, polaritonic, and metamaterial systems. This bound is purely defined by material properties and cannot be overcome by device design. Moreover it is frequency dependent in the presence of multiple Lorentz poles. We numerically verify this bound through direct calculations for a range of plasmonic systems, including optical antennas where the bound places fundamental performance constraints.
View details for DOI 10.1103/PhysRevLett.110.183901
View details for Web of Science ID 000319014400001
View details for PubMedID 23683195
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Compact bends for multi-mode photonic crystal waveguides with high transmission and suppressed modal crosstalk
OPTICS EXPRESS
2013; 21 (7): 8069-8075
Abstract
We demonstrate an extremely compact bend for a photonic crystal waveguide supporting three spatial modes. The bend exhibits nearly 100% transmission over a relative bandwidth of 1% with less than 1% crosstalk. We show that our design is robust with respect to fabrication errors. Our design method is applied to create a structure consisting of dielectric rods, as well as a structure consisting of air holes in a dielectric background.
View details for Web of Science ID 000317659300023
View details for PubMedID 23571897
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Ultrabroadband Photonic Structures To Achieve High-Performance Daytime Radiative Cooling
NANO LETTERS
2013; 13 (4): 1457-1461
Abstract
If properly designed, terrestrial structures can passively cool themselves through radiative emission of heat to outer space. For the first time, we present a metal-dielectric photonic structure capable of radiative cooling in daytime outdoor conditions. The structure behaves as a broadband mirror for solar light, while simultaneously emitting strongly in the mid-IR within the atmospheric transparency window, achieving a net cooling power in excess of 100 W/m(2) at ambient temperature. This cooling persists in the presence of significant convective/conductive heat exchange and nonideal atmospheric conditions.
View details for DOI 10.1021/nl4004283
View details for Web of Science ID 000317549300016
View details for PubMedID 23461597
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Experimental Assessment of the Accuracy of an Advanced Photonic-Bandgap-Fiber Model
JOURNAL OF LIGHTWAVE TECHNOLOGY
2013; 31 (7): 1015-1022
View details for DOI 10.1109/JLT.2013.2238608
View details for Web of Science ID 000314694100001
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Fluorescence Correlation Spectroscopy at High Concentrations using Gold Bowtie Nanoantennas (vol 406C, pg 3, 2012)
CHEMICAL PHYSICS
2013; 415: 309-309
View details for DOI 10.1016/j.chemphys.2013.02.003
View details for Web of Science ID 000317277300042
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Temporal coupled mode theory for thermal emission from a single thermal emitter supporting either a single mode or an orthogonal set of modes
APPLIED PHYSICS LETTERS
2013; 102 (10)
View details for DOI 10.1063/1.4794981
View details for Web of Science ID 000316501200067
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Experimental demonstration of a photonic Aharonov-Bohm effect at radio frequencies
PHYSICAL REVIEW B
2013; 87 (6)
View details for DOI 10.1103/PhysRevB.87.060301
View details for Web of Science ID 000314992700001
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Highly Tailored Computational Electromagnetics Methods for Nanophotonic Design and Discovery
PROCEEDINGS OF THE IEEE
2013; 101 (2): 484-493
View details for DOI 10.1109/JPROC.2012.2207649
View details for Web of Science ID 000313724400021
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Transparent and conductive paper from nanocellulose fibers
ENERGY & ENVIRONMENTAL SCIENCE
2013; 6 (2): 513-518
View details for DOI 10.1039/c2ee23635d
View details for Web of Science ID 000313892400013
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Tight-binding calculation of radiation loss in photonic crystal CROW
OPTICS EXPRESS
2013; 21 (2): 2463-2473
Abstract
The tight binding approximation (TBA) is used to relate the intrinsic, radiation loss of a coupled resonator optical waveguide (CROW) to that of a single constituent resonator within a light cone picture. We verify the validity of the TBA via direct, full-field simulation of CROWs based on the L2 photonic crystal cavity. The TBA predicts that the quality factor of the CROW increases with that of the isolated cavity. Moreover, our results provide a method to design CROWs with low intrinsic loss across the entire waveguide band.
View details for Web of Science ID 000315989500110
View details for PubMedID 23389227
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Fundamental bounds on decay rates in asymmetric single-mode optical resonators
OPTICS LETTERS
2013; 38 (2): 100-102
Abstract
We derive tight upper and lower bounds of the ratio between decay rates to two ports from a single resonance exhibiting Fano interference, based on a general temporal coupled-mode theory formalism. The photon transport between these two ports involves both direct and resonance-assisted contributions, and the bounds depend only on the direct process. The bounds imply that, in a lossless system, full reflection is always achievable at Fano resonance, even for structures lacking mirror symmetries, while full transmission can only be seen in a symmetric configuration where the two decay rates are equal. The analytic predictions are verified against full-field electromagnetic simulations.
View details for Web of Science ID 000313636600007
View details for PubMedID 23454928
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Detailed balance analysis of nanophotonic solar cells
OPTICS EXPRESS
2013; 21 (1): 1209-1217
Abstract
We present a detailed balance based approach for performing current density-voltage characteristic modeling of nanophotonic solar cells. This approach takes into account the intrinsic material non-idealities, and is useful for determining the theoretical limit of solar cell efficiency for a given structure. Our approach only requires the cell's absorption spectra over all angles, which can be readily calculated using available simulation tools. Using this approach, we elucidate the physics of open-circuit voltage enhancement over bulk cells in nanoscale thin film structures, by showing that the enhancement is related to the absorption suppression in the immediate spectral region above the bandgap. We also show that with proper design, the use of a grating on a nanoscale thin film can increase its short-circuit current, while preserving its voltage-enhancing capabilities.
View details for Web of Science ID 000315988100144
View details for PubMedID 23389013
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Routing of Deep-Subwavelength Optical Beams and Images without Reflection and Diffraction Using Infinitely Anisotropic Metamaterials
ADVANCED MATERIALS
2013; 25 (2): 194-198
Abstract
Interfaces between media with infinite anisotropy, defined by infinite permittivity or permeability in one direction, offer new opportunities for controlling and manipulating light at the nanoscale. Reflectionless, diffraction-free routing of deep-subwavelength optical beams and images using interfaces between infinitely anisotropic media are demonstrated. It is shown how to achieve extremely large anisotropy using metamaterial designs that can be implemented with existing materials.
View details for DOI 10.1002/adma.201203528
View details for Web of Science ID 000313262300005
View details for PubMedID 23180728
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Synthetic magnetic field directs photons
PHOTONICS SPECTRA
2013; 47 (1): 28-?
View details for Web of Science ID 000314482400008
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Limits on nanophotonic solar cell light trapping in the presence of parasitic losses
IEEE. 2013
View details for Web of Science ID 000355262502168
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Enhancing far-field thermal emission with thermal extraction
IEEE. 2013
View details for Web of Science ID 000355262503249
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Dispersion control of near-infrared surface plasmon polariton using hyperbolic metamaterials
IEEE. 2013
View details for Web of Science ID 000355262504118
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Temporal Coupled mode theory for thermal emission from a single emitter
IEEE. 2013
View details for Web of Science ID 000355262505137
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Broadband Management of Light Using Nanophotonics for Solar and Thermal Applications
IEEE. 2013
View details for Web of Science ID 000355316301568
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Transfer Printed Nanomembrane High-Q Filters Based on Displaced Double-Layer Fano Resonance Photonic Crystal Slabs
IEEE. 2013: 444-445
View details for Web of Science ID 000369918000221
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Plasmonic nano-coaxial waveguides for 90-degree bends and T-splitters
IEEE. 2013
View details for Web of Science ID 000355262505334
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Inducing Electro-Optic Photonic Transitions for Enabling Isolation in Silicon Photonics
IEEE-Photonics-Society Summer Topical Meeting
IEEE. 2013: 205–205
View details for Web of Science ID 000333963600098
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Large-Area Free-Standing Ultrathin Single-Crystal Silicon as Processable Materials
Nano Letters
2013: 4393–98
Abstract
Silicon has been driving the great success of semiconductor industry, and emerging forms of silicon have generated new opportunities in electronics, biotechnology, and energy applications. Here we demonstrate large-area free-standing ultrathin single-crystalline Si at the wafer scale as new Si materials with processability. We fabricated them by KOH etching of the Si wafer and show their uniform thickness from 10 to sub-2 μm. These ultrathin Si exhibits excellent mechanical flexibility and bendability more than those with 20-30 μm thickness in previous study. Unexpectedly, these ultrathin Si materials can be cut with scissors like a piece of paper, and they are robust during various regular fabrication processings including tweezer handling, spin coating, patterning, doping, wet and dry etching, annealing, and metal deposition. We demonstrate the fabrication of planar and double-sided nanocone solar cells and highlight that the processability on both sides of surface together with the interesting property of these free-standing ultrathin Si materials opens up exciting opportunities to generate novel functional devices different from the existing approaches.
View details for DOI 10.1021/nl402230v
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Tight-binding calculation of radiation loss in photonic crystal CROW
IEEE. 2013
View details for Web of Science ID 000355262504074
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Optimization of non-periodic plasmonic light-trapping layers for thin-film solar cells.
Nature communications
2013; 4: 2095-?
Abstract
Non-periodic arrangements of nanoscale light scatterers allow for the realization of extremely effective broadband light-trapping layers for solar cells. However, their optimization is challenging given the massive number of degrees of freedom. Brute-force, full-field electromagnetic simulations are computationally too time intensive to identify high-performance solutions in a vast design space. Here we illustrate how a semi-analytical model can be used to quickly identify promising non-periodic spatial arrangements of nanoscale scatterers. This model only requires basic knowledge of the scattering behaviour of a chosen nanostructure and the waveguiding properties of the semiconductor layer in a cell. Due to its simplicity, it provides new intuition into the ideal amount of disorder in high-performance light-trapping layers. Using simulations and experiments, we demonstrate that arrays of nanometallic stripes featuring a limited amount of disorder, for example, following a quasi-periodic or Fibonacci sequence, can substantially enhance solar absorption over perfectly periodic and random arrays.
View details for DOI 10.1038/ncomms3095
View details for PubMedID 23817445
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Optimization of non-periodic plasmonic light-trapping layers for thin-film solar cells.
Nature communications
2013; 4: 2095-?
View details for DOI 10.1038/ncomms3095
View details for PubMedID 23817445
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Modeling Loss and Backscattering in a Photonic-Bandgap Fiber Using Strong Perturbation
Conference on Photonic and Phononic Properties of Engineered Nanostructures III
SPIE-INT SOC OPTICAL ENGINEERING. 2013
View details for DOI 10.1117/12.2006446
View details for Web of Science ID 000322962900014
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Photonic structures: advanced thermal control, and effective gauge field for light
7th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics (METAMATERIALS)
IEEE. 2013: 232–233
View details for Web of Science ID 000352010200078
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Manipulating Thermal Electromagnetic Fields by Engineering Nanophotonic Resonances
10th Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)
IEEE. 2013
View details for Web of Science ID 000334176100172
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Local density of states of chiral Hall edge states in gyrotropic photonic clusters
Physical Review B
2013; 88 (3)
View details for DOI 10.1103/PhysRevB.88.035127
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Color-preserving daytime radiative cooling
Applied Physics Letters
2013; 103 (22)
View details for DOI 10.1063/1.4835995
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Effective magnetic field for photons based on the magneto-optical effect
Physical Review A
2013; 88 (4)
View details for DOI 10.1103/PhysRevA.88.043847
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Deep subwavelength plasmonic waveguide switch in double graphene layer structure
Applied Physics Letters
2013; 103 (23)
View details for DOI 10.1063/1.4839420
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What is - and what is not - an optical isolator
Nature Photonics
2013; 7 (8): 579-582
View details for DOI 10.1038/nphoton.2013.185
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Upper Bound on the Modal Material Loss Rate in Plasmonic and Metamaterial Systems
Physical Review Letters
2013; 110 (18)
View details for DOI 10.1103/PhysRevLett.110.183901
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Two-photon transport through a waveguide coupling to a whispering-gallery resonator containing an atom and photon-blockade effect
Physical Review A
2013; 87 (6)
View details for DOI 10.1103/PhysRevA.87.063818
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Two-Dimensional Chalcogenide Nanoplates as Tunable Metamaterials via Chemical Intercalation
Nano Letters
2013; 13 (12): 5913-5918
View details for DOI 10.1021/nl402937g
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Metamaterial band theory: fundamentals & applications
Science China-Information Sciences
2013; 56 (12)
View details for DOI 10.1007/s11432-013-5039-7
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Experimental demonstration of a photonic Aharonov-Bohm effect at radio frequencies
Physical Review B
2013; 87 (6)
View details for DOI 10.1103/PhysRevB.87.060301
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Coupled double-layer Fano resonance photonic crystal filters with lattice-displacement
Applied Physics Letters
2013; 103 (24)
View details for DOI 10.1063/1.4846475
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Analytic Properties of Two-Photon Scattering Matrix in Integrated Quantum Systems Determined by the Cluster Decomposition Principle
Physical Review Letters
2013; 111 (22)
View details for DOI 10.1103/PhysRevLett.111.223602
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Enhancing far-field thermal emission with thermal extraction
Nature Communications
2013; 4
View details for DOI 10.1038/ncomms2765
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Ultrahigh-contrast and large-bandwidth thermal rectification in near-field electromagnetic thermal transfer between nanoparticles
Physical Review B
2013; 88 (18)
View details for DOI 10.1103/PhysRevB.88.184300
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Three-dimensional self-assembled photonic crystals with high temperature stability for thermal emission modification
Nature Communications
2013; 4
View details for DOI 10.1038/ncomms3630
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Fluorescence Correlation Spectroscopy at High Concentrations using Gold Bowtie Nanoantennas (vol 406C, pg 3, 2012)
Chemical Physics
2013; 415: 309
View details for DOI 10.1016/j.chemphys.2013.02.003
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Controlling the Flow of Light Using the Inhomogeneous Effective Gauge Field that Emerges from Dynamic Modulation
Physical Review Letters
2013; 111 (20)
View details for DOI 10.1103/PhysRevLett.111.203901
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Wireless power transfer in the presence of metallic plates: Experimental results
Aip Advances
2013; 3 (6)
View details for DOI 10.1063/1.4809665
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Temporal coupled mode theory for thermal emission from a single thermal emitter supporting either a single mode or an orthogonal set of modes
Applied Physics Letters
2013; 102 (10)
View details for DOI 10.1063/1.4794981
-
Optimization of non-periodic plasmonic light-trapping layers for thin-film solar cells
Nature Communications
2013; 4
View details for DOI 10.1038/ncomms3095
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Modal Source Radiator Model for Arbitrary Two-Dimensional Arrays of Subwavelength Apertures on Metal Films
Ieee Journal of Selected Topics in Quantum Electronics
2013; 19 (3)
View details for DOI 10.1109/jstqe.2012.2229383
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A transparent electrode based on a metal nanotrough network
Nature Nanotechnology
2013; 8 (6): 421-425
Abstract
Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide-the prototypical transparent electrode material-demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10Ω □(-1) at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ∼2Ω □(-1) at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.
View details for DOI 10.1038/nnano.2013.84
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Broadband Sharp 90-degree Bends and T-Splitters in Plasmonic Coaxial Waveguides
Nano Letters
2013; 13 (10): 4753-4758
Abstract
We demonstrate numerically that sharp 90° bends and T-splitters can be designed in plasmonic coaxial waveguides at deep-subwavelength scale to operate without reflection and radiation over a broad range of wavelengths, including the telecommunication wavelength of 1.55 μm. We explain the principles of the operation using a transmission line model of the waveguide in the quasi-static limit. The compact bends and T-splitters open up a new avenue for the design of densely integrated optical circuits with minimal crosstalk.
View details for DOI 10.1021/nl402335x
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Enhancing far-field thermal emission with thermal extraction.
Nature communications
2013; 4: 1730-?
Abstract
The control of thermal radiation is of great current importance for applications such as energy conversions and radiative cooling. Here we show theoretically that the thermal emission of a finite-size blackbody emitter can be enhanced in a thermal extraction scheme, where one places the emitter in optical contact with an extraction device consisting of a transparent object, as long as both the emitter and the extraction device have an internal density of state higher than vacuum, and the extraction device has an area larger than the emitter and moreover has a geometry that enables light extraction. As an experimental demonstration of the thermal extraction scheme, we observe a four-fold enhancement of the far-field thermal emission of a carbon-black emitter having an emissivity of 0.85.
View details for DOI 10.1038/ncomms2765
View details for PubMedID 23591897
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Enhancing the waveguide-resonator optical force with an all-optical on-chip analog of electromagnetically induced transparency
PHYSICAL REVIEW A
2012; 86 (6)
View details for DOI 10.1103/PhysRevA.86.063833
View details for Web of Science ID 000312829800038
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Ultra-compact photonic crystal waveguide spatial mode converter and its connection to the optical diode effect
OPTICS EXPRESS
2012; 20 (27): 28388-28397
Abstract
We design an extremely compact photonic crystal waveguide spatial mode converter which converts the fundamental even mode to the higher order odd mode with nearly 100% efficiency. We adapt a previously developed design and optimization process that allows these types of devices to be designed in a matter of minutes. We also present an extremely compact optical diode device and clarify its general properties and its relation to spatial mode converters. Finally, we connect the results here to a general theory on the complexity of optical designs.
View details for PubMedID 23263074
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A simple Bayesian decision-theoretic design for dose-finding trials
STATISTICS IN MEDICINE
2012; 31 (28): 3719-3730
Abstract
A flexible and simple Bayesian decision-theoretic design for dose-finding trials is proposed in this paper. In order to reduce the computational burden, we adopt a working model with conjugate priors, which is flexible to fit all monotonic dose-toxicity curves and produces analytic posterior distributions. We also discuss how to use a proper utility function to reflect the interest of the trial. Patients are allocated based on not only the utility function but also the chosen dose selection rule. The most popular dose selection rule is the one-step-look-ahead (OSLA), which selects the best-so-far dose. A more complicated rule, such as the two-step-look-ahead, is theoretically more efficient than the OSLA only when the required distributional assumptions are met, which is, however, often not the case in practice. We carried out extensive simulation studies to evaluate these two dose selection rules and found that OSLA was often more efficient than two-step-look-ahead under the proposed Bayesian structure. Moreover, our simulation results show that the proposed Bayesian method's performance is superior to several popular Bayesian methods and that the negative impact of prior misspecification can be managed in the design stage.
View details for DOI 10.1002/sim.5438
View details for Web of Science ID 000311402300021
View details for PubMedID 22763943
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On the Time to Conclusion of Phase II Cancer Clinical Trials and Its Application in Trial Designs
STATISTICS IN BIOPHARMACEUTICAL RESEARCH
2012; 4 (4): 324-335
View details for DOI 10.1080/19466315.2012.695258
View details for Web of Science ID 000309751000002
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Realizing effective magnetic field for photons by controlling the phase of dynamic modulation
NATURE PHOTONICS
2012; 6 (11): 782-787
View details for DOI 10.1038/NPHOTON.2012.236
View details for Web of Science ID 000310848300020
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Few-Photon Single-Atom Cavity QED With Input-Output Formalism in Fock Space
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2012; 18 (6): 1754-1762
View details for DOI 10.1109/JSTQE.2012.2196261
View details for Web of Science ID 000308664900016
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Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures
PHYSICAL REVIEW LETTERS
2012; 109 (17)
Abstract
The coupling between free space radiation and optical media critically influences the performance of optical devices. We show that, for any given photonic structure, the sum of the external coupling rates for all its optical modes are subject to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers.
View details for DOI 10.1103/PhysRevLett.109.173901
View details for Web of Science ID 000310200100011
View details for PubMedID 23215189
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Fluorescence correlation spectroscopy at high concentrations using gold bowtie nanoantennas
CHEMICAL PHYSICS
2012; 406: 3-8
View details for DOI 10.1016/j.chemphys.2012.04.011
View details for Web of Science ID 000310569800002
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Optical Absorption Enhancement in Freestanding GaAs Thin Film Nanopyramid Arrays
ADVANCED ENERGY MATERIALS
2012; 2 (10): 1254-1260
View details for DOI 10.1002/aenm.201200022
View details for Web of Science ID 000309595900014
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S-4: A free electromagnetic solver for layered periodic structures
COMPUTER PHYSICS COMMUNICATIONS
2012; 183 (10): 2233-2244
View details for DOI 10.1016/j.cpc.2012.04.026
View details for Web of Science ID 000306771900020
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Design for broadband on-chip isolator using stimulated Brillouin scattering in dispersion-engineered chalcogenide waveguides
OPTICS EXPRESS
2012; 20 (19): 21235-21246
Abstract
We propose a scheme for on-chip isolation in chalcogenide (As₂S₃) rib waveguides, in which Stimulated Brillouin Scattering is used to induce non-reciprocal mode conversion within a multi-moded waveguide. The design exploits the idea that a chalcogenide rib buried in a silica matrix acts as waveguide for both light and sound, and can also be designed to be multi-moded for both optical and acoustic waves. The enhanced opto-acoustic coupling allows significant isolation (> 20 dB) within a chip-scale (cm-long) device (< 10 cm). We also show that the bandwidth of this device can be dramatically increased by tuning the dispersion of the waveguide to match the group velocity between optical modes: we find that 20 dB isolation can be extended over a bandwidth of 25 nm.
View details for Web of Science ID 000308865600066
View details for PubMedID 23037247
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Near-Field Radiative Cooling of Nanostructures
NANO LETTERS
2012; 12 (9): 4546-4550
Abstract
We measure near-field radiative cooling of a thermally isolated nanostructure up to a few degrees and show that in principle this process can efficiently cool down localized hotspots by tens of degrees at submicrometer gaps. This process of cooling is achieved without any physical contact, in contrast to heat transfer through conduction, thus enabling novel cooling capabilities. We show that the measured trend of radiative cooling agrees well theoretical predictions and is limited mainly by the geometry of the probe used here as well as the minimum separation that could be achieved in our setup. These results also pave the way for realizing other new effects based on resonant heat transfer, like thermal rectification and negative thermal conductance.
View details for DOI 10.1021/nl301708e
View details for Web of Science ID 000308576000021
View details for PubMedID 22891815
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Photonic chip based tunable and reconfigurable narrowband microwave photonic filter using stimulated Brillouin scattering
OPTICS EXPRESS
2012; 20 (17): 18836-18845
Abstract
We report the first demonstration of a photonic chip based dynamically reconfigurable, widely tunable, narrow pass-band, high Q microwave photonic filter (MPF). We exploit stimulated Brillouin scattering (SBS) in a 6.5 cm long chalcogenide (As2S3) photonic chip to demonstrate a MPF that exhibited a high quality factor of ~520 and narrow bandwidth and was dynamically reconfigurable and widely tunable. It maintained a stable 3 dB bandwidth of 23 ± 2MHz and amplitude of 20 ± 2 dB over a large frequency tuning range of 2-12 GHz. By tailoring the pump spectrum, we reconfigured the 3 dB bandwidth of the MPF from ~20 MHz to ~40 MHz and tuned the shape factor from 3.5 to 2 resulting in a nearly flat-topped filter profile. This demonstration represents a significant advance in integrated microwave photonics with potential applications in on-chip microwave signal processing for RADAR and analogue communications.
View details for Web of Science ID 000307873600033
View details for PubMedID 23038523
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Electrically Driven Nonreciprocity Induced by Interband Photonic Transition on a Silicon Chip
PHYSICAL REVIEW LETTERS
2012; 109 (3)
Abstract
We demonstrate electrically driven nonreciprocity on a silicon chip. By achieving an indirect interband photonic transition, we show that the transmission coefficients between two single-mode waveguides become dependent on the propagation directions only in the presence of the electrical drive. Our structure is characterized by a nonsymmetric scattering matrix identical to a linear magneto-optical device.
View details for DOI 10.1103/PhysRevLett.109.033901
View details for Web of Science ID 000306417600002
View details for PubMedID 22861851
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Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide plates
JOURNAL OF APPLIED PHYSICS
2012; 112 (2)
View details for DOI 10.1063/1.4737465
View details for Web of Science ID 000308424500087
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Hybrid Silicon Nanocone-Polymer Solar Cells
NANO LETTERS
2012; 12 (6): 2971-2976
Abstract
Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm(2), which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution.
View details for DOI 10.1021/nl300713x
View details for Web of Science ID 000305106400054
View details for PubMedID 22545674
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High-Efficiency Amorphous Silicon Solar Cell on a Periodic Nanocone Back Reflector
ADVANCED ENERGY MATERIALS
2012; 2 (6): 628-633
View details for DOI 10.1002/aenm.201100514
View details for Web of Science ID 000305179000002
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Instantaneous electric energy and electric power dissipation in dispersive media
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2012; 29 (5): 1048-1054
View details for Web of Science ID 000303544000024
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Choice of the perfectly matched layer boundary condition for frequency-domain Maxwell's equations solvers
JOURNAL OF COMPUTATIONAL PHYSICS
2012; 231 (8): 3406-3431
View details for DOI 10.1016/j.jcp.2012.01.013
View details for Web of Science ID 000301901600021
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Temporal coupled-mode theory for light scattering by an arbitrarily shaped object supporting a single resonance
PHYSICAL REVIEW A
2012; 85 (4)
View details for DOI 10.1103/PhysRevA.85.043828
View details for Web of Science ID 000302958000007
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Photonic Aharonov-Bohm Effect Based on Dynamic Modulation
PHYSICAL REVIEW LETTERS
2012; 108 (15)
Abstract
We show that when the refractive index of a photonic system is harmonically modulated, the phase of the modulation introduces an effective gauge potential for photons. This effective gauge potential can be used to create a photonic Aharonov-Bohm effect. We show that the photonic Aharonov-Bohm effect provides the optimal mechanism for achieving complete on-chip nonmagnetic optical isolation.
View details for DOI 10.1103/PhysRevLett.108.153901
View details for Web of Science ID 000302703600004
View details for PubMedID 22587255
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Stimulated Emission from a Single Excited Atom in a Waveguide
PHYSICAL REVIEW LETTERS
2012; 108 (14)
Abstract
We study stimulated emission from an excited two-level atom coupled to a waveguide containing an incident single-photon pulse. We show that the strong photon correlation, as induced by the atom, plays a very important role in stimulated emission. Additionally, the temporal duration of the incident photon pulse is shown to have a marked effect on stimulated emission and atomic lifetime.
View details for DOI 10.1103/PhysRevLett.108.143602
View details for Web of Science ID 000302293500010
View details for PubMedID 22540793
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Resonant Fiber Optic Gyroscope Using an Air-Core Fiber
JOURNAL OF LIGHTWAVE TECHNOLOGY
2012; 30 (7): 931-937
View details for DOI 10.1109/JLT.2011.2177959
View details for Web of Science ID 000300578100001
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Absorption Enhancement in Ultrathin Crystalline Silicon Solar Cells with Antireflection and Light-Trapping Nanocone Gratings
NANO LETTERS
2012; 12 (3): 1616-1619
Abstract
Enhancing the light absorption in ultrathin-film silicon solar cells is important for improving efficiency and reducing cost. We introduce a double-sided grating design, where the front and back surfaces of the cell are separately optimized for antireflection and light trapping, respectively. The optimized structure yields a photocurrent of 34.6 mA/cm(2) at an equivalent thickness of 2 μm, close to the Yablonovitch limit. This approach is applicable to various thicknesses and is robust against metallic loss in the back reflector.
View details for DOI 10.1021/nl204550q
View details for Web of Science ID 000301406800086
View details for PubMedID 22356436
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From Electromagnetically Induced Transparency to Superscattering with a Single Structure: A Coupled-Mode Theory for Doubly Resonant Structures
PHYSICAL REVIEW LETTERS
2012; 108 (8)
Abstract
We observe from simulations that a doubly resonant structure can exhibit spectral behavior analogous to electromagnetically induced transparency, as well as superscattering, depending on the excitation. We develop a coupled-mode theory that explains this behavior in terms of the orthogonality of the radiation patterns of the eigenmodes. These results provide insight in the general electromagnetic properties of photonic nanostructures and metamaterials.
View details for DOI 10.1103/PhysRevLett.108.083902
View details for Web of Science ID 000300576000010
View details for PubMedID 22463532
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Resonance fluorescence in a waveguide geometry
PHYSICAL REVIEW A
2012; 85 (2)
View details for DOI 10.1103/PhysRevA.85.023817
View details for Web of Science ID 000300417300003
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Lossless intensity modulation in integrated photonics
OPTICS EXPRESS
2012; 20 (4): 4280-4290
Abstract
We present a dynamical analysis of lossless intensity modulation in two different ring resonator geometries. In both geometries, we demonstrate modulation schemes that result in a symmetrical output with an infinite on/off ratio. The systems behave as lossless intensity modulators where the time-averaged output optical power is equal to the time-averaged input optical power.
View details for Web of Science ID 000301041900093
View details for PubMedID 22418187
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Broadband light management using low-Q whispering gallery modes in spherical nanoshells
NATURE COMMUNICATIONS
2012; 3
Abstract
Light trapping across a wide band of frequencies is important for applications such as solar cells and photodetectors. Here, we demonstrate a new approach to light management by forming whispering-gallery resonant modes inside a spherical nanoshell structure. The geometry of the structure gives rise to a low quality-factor, facilitating the coupling of light into the resonant modes and substantial enhancement of the light path in the active material, thus dramatically improving absorption. Using nanocrystalline silicon (nc-Si) as a model system, we observe broadband absorption enhancement across a large range of incident angles. The absorption of a single layer of 50-nm-thick spherical nanoshells is equivalent to a 1-μm-thick planar nc-Si film. This light-trapping structure could enable the manufacturing of high-throughput ultra-thin film absorbers in a variety of material systems that demand shorter deposition time, less material usage and transferability to flexible substrates.
View details for DOI 10.1038/ncomms1664
View details for PubMedID 22314360
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Negative differential thermal conductance through vacuum
APPLIED PHYSICS LETTERS
2012; 100 (4)
View details for DOI 10.1063/1.3679694
View details for Web of Science ID 000300064500085
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Comment on "Nonreciprocal Light Propagation in a Silicon Photonic Circuit"
SCIENCE
2012; 335 (6064)
Abstract
We show that the structure demonstrated by Feng et al. (Reports, 5 August 2011, p. 729) cannot enable optical isolation because it possesses a symmetric scattering matrix. Moreover, one cannot construct an optical isolator by incorporating this structure into any system as long as the system is linear and time-independent and is described by materials with a scalar dielectric function.
View details for DOI 10.1126/science.1216682
View details for PubMedID 22223793
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Temperature dependence of surface phonon polaritons from a quartz grating (vol 110, 043517, 2011)
JOURNAL OF APPLIED PHYSICS
2012; 111 (1)
View details for DOI 10.1063/1.3665444
View details for Web of Science ID 000299127200132
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Stacked Fano Resonance Photonic Crystal Nanomembrane High-Q Filters
25th IEEE Photonics Conference (IPC)
IEEE. 2012: 721–722
View details for Web of Science ID 000312865000358
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From electromagnetically induced transparency to superscattering with a single structure: A coupled-mode theory for doubly resonant structures
SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.909576
View details for Web of Science ID 000302582400010
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Electro-optical silicon isolator
IEEE. 2012
View details for Web of Science ID 000310362401324
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Resonance Fluorescence in a Waveguide Geometry
IEEE. 2012
View details for Web of Science ID 000310362403222
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GaAs thin film nanostructure arrays for III-V solar cell applications
Conference on Photonic and Phononic Properties of Engineered Nanostructures II
SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.909743
View details for Web of Science ID 000302582400036
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Slow Light in Fiber Sensors
Conference on Advances in Slow and Fast Light V
SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.915293
View details for Web of Science ID 000305324800014
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From Electromagnetically Induced Transparency to Superscattering with a Single Structure: A Coupled-Mode Theory for Doubly Resonant Structures
Physical Review Letters
2012; 108 (8)
View details for DOI 083902 10.1103/PhysRevLett.108.083902
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Temporal coupled-mode theory for light scattering by an arbitrarily shaped object supporting a single resonance
Physical Review A
2012; 85 (4)
View details for DOI 043828 10.1103/PhysRevA.85.043828
-
Resonance fluorescence in a waveguide geometry
Physical Review A
2012; 85 (2)
View details for DOI 023817 10.1103/PhysRevA.85.023817
-
Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures
Physical Review Letters
2012; 109 (17)
View details for DOI 10.1103/PhysRevLett.109.173901
-
Temperature dependence of surface phonon polaritons from a quartz grating (vol 110, 043517, 2011)
Journal of Applied Physics
2012; 111 (1)
View details for DOI 019902 10.1063/1.3665444
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Photonic Aharonov-Bohm Effect Based on Dynamic Modulation
Physical Review Letters
2012; 108 (15)
View details for DOI 153901 10.1103/PhysRevLett.108.153901
-
Negative differential thermal conductance through vacuum
Applied Physics Letters
2012; 100 (4)
View details for DOI 044104 10.1063/1.3679694
-
Comment on "Nonreciprocal Light Propagation in a Silicon Photonic Circuit
Science
2012; 335 (6064): 38; author reply 38
Abstract
We show that the structure demonstrated by Feng et al. (Reports, 5 August 2011, p. 729) cannot enable optical isolation because it possesses a symmetric scattering matrix. Moreover, one cannot construct an optical isolator by incorporating this structure into any system as long as the system is linear and time-independent and is described by materials with a scalar dielectric function.
View details for DOI 10.1126/science.1216682
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Broadband light management using low-Q whispering gallery modes in spherical nanoshells
Nature Communications
2012; 3
View details for DOI 664 10.1038/ncomms1664
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Stimulated Emission from a Single Excited Atom in a Waveguide
Physical Review Letters
2012; 108 (14)
View details for DOI 143602 10.1103/PhysRevLett.108.143602
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Enhancing the waveguide-resonator optical force with an all-optical on-chip analog of electromagnetically induced transparency
Physical Review A
2012; 86 (6)
View details for DOI 10.1103/PhysRevA.86.063833
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Electrically Driven Nonreciprocity Induced by Interband Photonic Transition on a Silicon Chip
Physical Review Letters
2012; 109 (3)
View details for DOI 10.1103/PhysRevLett.109.033901
-
Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide plates
Journal of Applied Physics
2012; 112 (2)
View details for DOI 10.1063/1.4737465
-
Extraordinarily high spectral sensitivity in refractive index sensors using multiple optical modes
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2012
View details for Web of Science ID 000310362403063
-
Deep sub-wavelength beam propagation, beam manipulation and imaging with extreme anisotropic meta-materials
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2012
View details for Web of Science ID 000310362403204
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Photonic transitions can induce non-reciprocity and effective gauge field for photons
5th International Workshop on Theoretical and Computational Nano-Photonics (TaCoNa-Photonics)
AMER INST PHYSICS. 2012: 16–17
View details for DOI 10.1063/1.4750080
View details for Web of Science ID 000309602000005
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Choice of the Perfectly Matched Layer boundary condition for iterative solvers of the frequency-domain Maxwell's equations
Conference on Physics and Simulation of Optoelectronic Devices XX
SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.906869
View details for Web of Science ID 000302993700016
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Improving fiber optic gyroscope performance using a laser and photonic-bandgap fiber
22nd International Conference on Optical Fiber Sensors (OFS)
SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.2000380
View details for Web of Science ID 000313011500009
-
Sensing With Slow Light in Fiber Bragg Gratings
IEEE SENSORS JOURNAL
2012; 12 (1): 156-163
View details for DOI 10.1109/JSEN.2011.2135343
View details for Web of Science ID 000297631700026
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Optical Transmission through Arbitrarily Located Subwavelength Apertures on Metal Films
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2012
View details for Web of Science ID 000310362403119
-
Numerically exact calculation of electromagnetic heat transfer between a dielectric sphere and plate
PHYSICAL REVIEW B
2011; 84 (24)
View details for DOI 10.1103/PhysRevB.84.245431
View details for Web of Science ID 000298116400010
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Few-photon transport in a waveguide coupled to a pair of colocated two-level atoms
PHYSICAL REVIEW A
2011; 84 (6)
View details for DOI 10.1103/PhysRevA.84.063832
View details for Web of Science ID 000298113300010
-
Two-photon transport in a waveguide coupled to a cavity in a two-level system
PHYSICAL REVIEW A
2011; 84 (6)
View details for DOI 10.1103/PhysRevA.84.063803
View details for Web of Science ID 000297546700004
-
Wireless energy transfer with the presence of metallic planes
APPLIED PHYSICS LETTERS
2011; 99 (21)
View details for DOI 10.1063/1.3663576
View details for Web of Science ID 000297471000055
-
Nanophotonic light-trapping theory for solar cells
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
2011; 105 (2): 329-339
View details for DOI 10.1007/s00339-011-6617-4
View details for Web of Science ID 000296877900009
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Ultracompact nonreciprocal optical isolator based on guided resonance in a magneto-optical photonic crystal slab
OPTICS LETTERS
2011; 36 (21): 4254-4256
Abstract
We design an ultracompact optical isolator with normal incident geometry that operates with a bandwidth that is substantial for a device of this size. For operation in a telecommunication wavelength of 1.55 μm, the thickness of the device is less than 1 μm and the device supports an operating bandwidth of 400 GHz over which the minimum contrast ratio exceeds 25 dB. Our design utilizes guided resonance in a photonic crystal slab to enhance magneto-optical effects, and exploits interference effects among multiple resonances to create desired transmission spectral line shapes.
View details for Web of Science ID 000296734700045
View details for PubMedID 22048382
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Dielectric nanostructures for broadband light trapping in organic solar cells
OPTICS EXPRESS
2011; 19 (20): 19015-19026
Abstract
Organic bulk heterojunction solar cells are a promising candidate for low-cost next-generation photovoltaic systems. However, carrier extraction limitations necessitate thin active layers that sacrifice absorption for internal quantum efficiency or vice versa. Motivated by recent theoretical developments, we show that dielectric wavelength-scale grating structures can produce significant absorption resonances in a realistic organic cell architecture. We numerically demonstrate that 1D, 2D and multi-level ITO-air gratings lying on top of the organic solar cell stack produce a 8-15% increase in photocurrent for a model organic solar cell where PCDTBT:PC(71)BM is the organic semiconductor. Specific to this approach, the active layer itself remains untouched yet receives the benefit of light trapping by nanostructuring the top surface below which it lies. The techniques developed here are broadly applicable to organic semiconductors in general, and enable partial decoupling between active layer thickness and photocurrent generation.
View details for Web of Science ID 000295373800026
View details for PubMedID 21996842
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OPTICAL ISOLATION A non-magnetic approach
NATURE PHOTONICS
2011; 5 (9): 517-519
View details for DOI 10.1038/nphoton.2011.216
View details for Web of Science ID 000294412700006
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Temperature dependence of surface phonon polaritons from a quartz grating
JOURNAL OF APPLIED PHYSICS
2011; 110 (4)
View details for DOI 10.1063/1.3624603
View details for Web of Science ID 000294484300037
-
Microscopic theory of photonic one-way edge mode
PHYSICAL REVIEW B
2011; 84 (7)
View details for DOI 10.1103/PhysRevB.84.075477
View details for Web of Science ID 000293830800017
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Complete All-Optical Silica Fiber Isolator via Stimulated Brillouin Scattering
JOURNAL OF LIGHTWAVE TECHNOLOGY
2011; 29 (15): 2267-2275
View details for DOI 10.1109/JLT.2011.2158886
View details for Web of Science ID 000293712700001
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Efficient computation of equifrequency surfaces and density of states in photonic crystals using Dirichlet-to-Neumann maps
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2011; 28 (8): 1837-1843
View details for Web of Science ID 000293330800009
-
Nonvolatile bistable all-optical switch from mechanical buckling
APPLIED PHYSICS LETTERS
2011; 98 (24)
View details for DOI 10.1063/1.3600335
View details for Web of Science ID 000291803600004
-
Transverse Electromagnetic Modes in Aperture Waveguides Containing a Metamaterial with Extreme Anisotropy
PHYSICAL REVIEW LETTERS
2011; 106 (22)
Abstract
We use metamaterials with extreme anisotropy to solve the fundamental problem of light transport in deep subwavelength apertures. By filling a simply connected aperture with an anisotropic medium, we decouple the cutoff frequency and the group velocity of modes inside apertures. In the limit of extreme anisotropy, all modes become purely transverse electromagnetic modes, free from geometrical dispersion, propagate with a velocity controlled by the transverse permittivity and permeability, and have zero cutoff frequency. We analyze physically realizable cases for a circular aperture and show a metamaterial design using existing materials.
View details for DOI 10.1103/PhysRevLett.106.223902
View details for Web of Science ID 000291199000006
View details for PubMedID 21702600
-
Perturbation theory for plasmonic modulation and sensing
PHYSICAL REVIEW B
2011; 83 (20)
View details for DOI 10.1103/PhysRevB.83.205131
View details for Web of Science ID 000290943800006
-
Extraordinarily high spectral sensitivity in refractive index sensors using multiple optical modes
OPTICS EXPRESS
2011; 19 (11): 10029-10040
Abstract
The extraordinary spectral sensitivity of surface plasmon resonance (SPR) sensors is commonly attributed to the modal overlap or unique dispersion of surface plasmons. In contrast to this belief, we show that such high sensitivity is due to the multi-mode nature of the sensing scheme. This concept of multi-mode sensing can be applied to dielectric systems as well in order to achieve similar extraordinary spectral sensitivity. We also show that there is a fundamental constraint between the spectral sensitivity and quality factor in such multi-mode sensing approach.
View details for Web of Science ID 000290852800001
View details for PubMedID 21643261
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Image transfer with subwavelength resolution to metal-dielectric interface
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2011; 28 (5): 1335-1338
View details for Web of Science ID 000290026800054
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Experimental demonstration of two methods for controlling the group delay in a system with photonic-crystal resonators coupled to a waveguide
OPTICS LETTERS
2011; 36 (8): 1482-1484
Abstract
We measure the group delay in an on-chip photonic-crystal device with two resonators side coupled to a waveguide. We demonstrate that such a group delay can be controlled by tuning either the propagation phase of the waveguide or the frequency of the resonators.
View details for Web of Science ID 000290034500059
View details for PubMedID 21499397
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Design methodology for compact photonic-crystal-based wavelength division multiplexers
OPTICS LETTERS
2011; 36 (4): 591-593
Abstract
We present an extremely compact wavelength division multiplexer design, as well as a general framework for designing and optimizing frequency selective devices embedded in photonic crystals satisfying arbitrary design constraints. Our method is based on the Dirichlet-to-Neumman simulation method and uses low rank updates to the system to efficiently scan through many device designs.
View details for Web of Science ID 000287395500055
View details for PubMedID 21326466
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Design of subwavelength superscattering nanospheres
APPLIED PHYSICS LETTERS
2011; 98 (4)
View details for DOI 10.1063/1.3536475
View details for Web of Science ID 000286676600041
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Low Reflectivity and High Flexibility of Tin-Doped Indium Oxide Nanofiber Transparent Electrodes
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
2011; 133 (1): 27-29
Abstract
Tin-doped indium oxide (ITO) has found widespread use in solar cells, displays, and touch screens as a transparent electrode; however, two major problems with ITO remain: high reflectivity (up to 10%) and insufficient flexibility. Together, these problems severely limit the applications of ITO films for future optoelectronic devices. In this communication, we report the fabrication of ITO nanofiber network transparent electrodes. The nanofiber networks show optical reflectivity as low as 5% and high flexibility; the nanofiber networks can be bent to a radius of 2 mm with negligible changes in the sheet resistance.
View details for DOI 10.1021/ja109228e
View details for Web of Science ID 000286351100009
View details for PubMedID 21142042
-
Angular constraint on light-trapping absorption enhancement in solar cells
APPLIED PHYSICS LETTERS
2011; 98 (1)
View details for DOI 10.1063/1.3532099
View details for Web of Science ID 000286009800007
-
Integrated photonic structures for parallel fluorescence and refractive index biosensing
Conference on Photonic Microdevices/Microstructures for Sensing III
SPIE-INT SOC OPTICAL ENGINEERING. 2011
View details for DOI 10.1117/12.884228
View details for Web of Science ID 000294154700005
-
Near shot-noise-limited performance of an open-loop laser-driven interferometric fiber optic gyroscope
21st International Conference on Optical Fiber Sensors
SPIE-INT SOC OPTICAL ENGINEERING. 2011
View details for DOI 10.1117/12.899550
View details for Web of Science ID 000293567800362
-
Wireless energy transfer with the presence of metallic planes
Applied Physics Letters
2011; 99 (21)
View details for DOI 214102 10.1063/1.3663576
-
Nanophotonic light-trapping theory for solar cells
Applied Physics a-Materials Science & Processing
2011; 2: 105
View details for DOI 10.1007/s00339-011-6617-4
-
Angular constraint on light-trapping absorption enhancement in solar cells
Applied Physics Letters
2011; 98 (1)
View details for DOI 011106 10.1063/1.3532099
-
Two-photon transport in a waveguide coupled to a cavity in a two-level system
Physical Review A
2011; 84 (6)
View details for DOI 063803 10.1103/PhysRevA.84.063803
-
Temperature dependence of surface phonon polaritons from a quartz grating
ournal of Applied Physics
2011; 110 (4)
View details for DOI 043517 10.1063/1.3624603
-
Perturbation theory for plasmonic modulation and sensing
Physical Review B
2011; 83 (20)
View details for DOI 205131 10.1103/PhysRevB.83.205131
-
Few-photon transport in a waveguide coupled to a pair of colocated two-level atoms
Physical Review A
2011; 84 (6)
View details for DOI 063832 10.1103/PhysRevA.84.063832
-
Nonvolatile bistable all-optical switch from mechanical buckling
Applied Physics Letters
2011; 98 (24)
View details for DOI 241104 10.1063/1.3600335
-
Transverse Electromagnetic Modes in Aperture Waveguides Containing a Metamaterial with Extreme Anisotropy
Physical Review Letters
2011; 106 (22)
View details for DOI 223902 10.1103/PhysRevLett.106.223902
-
Numerically exact calculation of electromagnetic heat transfer between a dielectric sphere and plate
Physical Review B
2011; 84 (24)
View details for DOI 245431 10.1103/PhysRevB.84.245431
-
Microscopic theory of photonic one-way edge mode
Physical Review B
2011; 84 (7)
View details for DOI 075477 10.1103/PhysRevB.84.075477
-
Design of subwavelength superscattering nanospheres
Applied Physics Letters
2011; 98 (4)
View details for DOI 043101 10.1063/1.3536475
-
Transverse electro-magnetic modes in apertures filled with an extreme anisotropic meta-material
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2011
View details for Web of Science ID 000295612404039
-
Temporal Coupled-Mode Theory for Resonant Apertures
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2011
View details for Web of Science ID 000295612403367
-
Dielectric nanostructures for broadband light trapping in organic solar cells
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2011
View details for Web of Science ID 000295612401071
-
Tactical-grade interferometric fiber optic gyroscope driven with a narrow-linewidth laser
21st International Conference on Optical Fiber Sensors
SPIE-INT SOC OPTICAL ENGINEERING. 2011
View details for DOI 10.1117/12.886025
View details for Web of Science ID 000293567800067
-
Slow Light in Fiber Bragg Gratings
Conference on Advances in Slow and Fast Light IV
SPIE-INT SOC OPTICAL ENGINEERING. 2011
View details for DOI 10.1117/12.880795
View details for Web of Science ID 000293700300010
-
Tight Binding Model Study of Photonic One-Way Edge Mode
Conference on Lasers and Electro-Optics (CLEO)
IEEE. 2011
View details for Web of Science ID 000295612404123
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Input-output formalism for few-photon transport in one-dimensional nanophotonic waveguides coupled to a qubit
PHYSICAL REVIEW A
2010; 82 (6)
View details for DOI 10.1103/PhysRevA.82.063821
View details for Web of Science ID 000286739800004
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Elements for Plasmonic Nanocircuits with Three-Dimensional Slot Waveguides
ADVANCED MATERIALS
2010; 22 (45): 5120-?
View details for DOI 10.1002/adma.201001440
View details for Web of Science ID 000285396400010
View details for PubMedID 20859937
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Nanostructured photon management for high performance solar cells
MATERIALS SCIENCE & ENGINEERING R-REPORTS
2010; 70 (3-6): 330-340
View details for DOI 10.1016/j.mser.2010.06.018
View details for Web of Science ID 000285706100017
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Sensitivity enhancement in photonic crystal slab biosensors
OPTICS EXPRESS
2010; 18 (22): 22702-22714
Abstract
Refractive index sensitivity of guided resonances in photonic crystal slabs is analyzed. We show that modal properties of guided resonances strongly affect spectral sensitivity and quality factors, resulting in substantial enhancement of refractive index sensitivity. A three-fold spectral sensitivity enhancement is demonstrated for suspended slab designs, in contrast to designs with a slab resting over a substrate. Spectral sensitivity values are additionally shown to be unaffected by quality factor reductions, which are common to fabricated photonic crystal nano-structures. Finally, we determine that proper selection of photonic crystal slab design parameters permits biosensing of a wide range of analytes, including proteins, antigens, and cells. These photonic crystals are compatible with large-area biosensor designs, permitting direct access to externally incident optical beams in a microfluidic device.
View details for Web of Science ID 000283560400009
View details for PubMedID 21164609
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Fundamental limit of nanophotonic light trapping in solar cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2010; 107 (41): 17491-17496
Abstract
Establishing the fundamental limit of nanophotonic light-trapping schemes is of paramount importance and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping demonstrated that absorption enhancement in a medium cannot exceed a factor of 4n(2)/sin(2)θ, where n is the refractive index of the active layer, and θ is the angle of the emission cone in the medium surrounding the cell. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the conventional limit can be substantially surpassed when optical modes exhibit deep-subwavelength-scale field confinement, opening new avenues for highly efficient next-generation solar cells.
View details for DOI 10.1073/pnas.1008296107
View details for Web of Science ID 000282809700012
View details for PubMedID 20876131
View details for PubMedCentralID PMC2955111
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The MicroArray Quality Control (MAQC)-II study of common practices for the development and validation of microarray-based predictive models
PHARMACOGENOMICS JOURNAL
2010: S5-S16
View details for DOI 10.1038/nbt.1665
View details for Web of Science ID 000285268700003
-
Temporal coupled-mode theory for resonant apertures
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
2010; 27 (10): 1947-1956
View details for Web of Science ID 000282514500003
-
Exponential suppression of thermal conductance using coherent transport and heterostructures
PHYSICAL REVIEW B
2010; 82 (11)
View details for DOI 10.1103/PhysRevB.82.113105
View details for Web of Science ID 000282168700001
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Fundamental limit of light trapping in grating structures
OPTICS EXPRESS
2010; 18 (19): A366-A380
Abstract
We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n², but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile's symmetry on the absorption enhancement limit. Numerical simulations are applied to support the theory. Our findings provide general guidance for the design of grating structures for light-trapping solar cells.
View details for Web of Science ID 000285263500004
View details for PubMedID 21165067
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Full inversion of a two-level atom with a single-photon pulse in one-dimensional geometries
PHYSICAL REVIEW A
2010; 82 (3)
View details for DOI 10.1103/PhysRevA.82.033804
View details for Web of Science ID 000281650400011
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Tuning the coherent interaction in an on-chip photonic-crystal waveguide-resonator system
APPLIED PHYSICS LETTERS
2010; 97 (10)
View details for DOI 10.1063/1.3486686
View details for Web of Science ID 000282478800002
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Quantum critical coupling conditions for zero single-photon transmission through a coupled atom-resonator-waveguide system
PHYSICAL REVIEW A
2010; 82 (2)
View details for DOI 10.1103/PhysRevA.82.021802
View details for Web of Science ID 000281063500002
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The MicroArray Quality Control (MAQC)-IIII study of common practices for the development and validation of microarray-based predictive models
NATURE BIOTECHNOLOGY
2010; 28 (8): 827-U109
Abstract
Gene expression data from microarrays are being applied to predict preclinical and clinical endpoints, but the reliability of these predictions has not been established. In the MAQC-II project, 36 independent teams analyzed six microarray data sets to generate predictive models for classifying a sample with respect to one of 13 endpoints indicative of lung or liver toxicity in rodents, or of breast cancer, multiple myeloma or neuroblastoma in humans. In total, >30,000 models were built using many combinations of analytical methods. The teams generated predictive models without knowing the biological meaning of some of the endpoints and, to mimic clinical reality, tested the models on data that had not been used for training. We found that model performance depended largely on the endpoint and team proficiency and that different approaches generated models of similar performance. The conclusions and recommendations from MAQC-II should be useful for regulatory agencies, study committees and independent investigators that evaluate methods for global gene expression analysis.
View details for DOI 10.1038/nbt.1665
View details for Web of Science ID 000280757500023
View details for PubMedID 20676074
View details for PubMedCentralID PMC3315840
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Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in Optoelectronic Devices
NANO LETTERS
2010; 10 (8): 2944-2949
Abstract
We investigate the use of nanopatterned metallic films as transparent conductive electrodes in optoelectronic devices. We find that the physics of nanopatterned electrodes, which are often optically thin metallic films, differs from that of optically thick metallic films. We analyze the optical properties when performing a geometrical transformation that maintains the electrical properties. For one-dimensional patterns of metallic wires, the analysis favors tall and narrow wires. Our design principles remain valid for oblique incidence and readily carry over to two-dimensional patterns.
View details for DOI 10.1021/nl1011239
View details for Web of Science ID 000280728900035
View details for PubMedID 20698607
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Superscattering of Light from Subwavelength Nanostructures
PHYSICAL REVIEW LETTERS
2010; 105 (1)
Abstract
We provide a theoretical discussion of the scattering cross section of individual subwavelength structures. We show that, in principle, an arbitrarily large total cross section can be achieved, provided that one maximizes contributions from a sufficiently large number of channels. As a numerical demonstration, we present a subwavelength nanorod with a plasmonic-dielectric-plasmonic layer structure, where the scattering cross section far exceeds the single-channel limit, even in the presence of loss.
View details for DOI 10.1103/PhysRevLett.105.013901
View details for Web of Science ID 000279273600001
View details for PubMedID 20867445
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Optimization of the splice loss between photonic-bandgap fibers and conventional single-mode fibers
OPTICS LETTERS
2010; 35 (12): 1938-1940
Abstract
To understand the loss limitations of a splice between a hollow-core fiber and a conventional fiber, we use a numerical model to calculate the expected coupling loss between the NKT Photonics' HC-1550-02 fiber and a single-mode fiber (SMF) of arbitrary step-index profile. When the SMF parameters are optimized, the splice loss is predicted to be as low as approximately 0.6 dB. This minimum is believed to be largely due to mode-shape mismatch. These predictions are confirmed experimentally by optimizing the splice loss between this photonic-bandgap fiber and five SMFs with different mode-field diameters (MFDs) and V numbers. With the SMF-28 fiber, the measured loss is 1.3 dB, in excellent agreement with theory. Using a SMF with parameters close to the optimum values (MFD=7.2 microm and V=2.16), this loss was reduced to a new record value of 0.79 dB.
View details for Web of Science ID 000279435800004
View details for PubMedID 20548345
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Enhancing optical switching with coherent control
APPLIED PHYSICS LETTERS
2010; 96 (23)
View details for DOI 10.1063/1.3449572
View details for Web of Science ID 000278695900008
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Nanodome Solar Cells with Efficient Light Management and Self-Cleaning
NANO LETTERS
2010; 10 (6): 1979-1984
Abstract
Here for the first time, we demonstrate novel nanodome solar cells, which have periodic nanoscale modulation for all layers from the bottom substrate, through the active absorber to the top transparent contact. These devices combine many nanophotonic effects to both efficiently reduce reflection and enhance absorption over a broad spectral range. Nanodome solar cells with only a 280 nm thick hydrogenated amorphous silicon (a-Si:H) layer can absorb 94% of the light with wavelengths of 400-800 nm, significantly higher than the 65% absorption of flat film devices. Because of the nearly complete absorption, a very large short-circuit current of 17.5 mA/cm(2) is achieved in our nanodome devices. Excitingly, the light management effects remain efficient over a wide range of incident angles, favorable for real environments with significant diffuse sunlight. We demonstrate nanodome devices with a power efficiency of 5.9%, which is 25% higher than the flat film control. The nanodome structure is not in principle limited to any specific material system and its fabrication is compatible with most solar manufacturing; hence it opens up exciting opportunities for a variety of photovoltaic devices to further improve performance, reduce materials usage, and relieve elemental abundance limitations. Lastly, our nanodome devices when modified with hydrophobic molecules present a nearly superhydrophobic surface and thus enable self-cleaning solar cells.
View details for DOI 10.1021/nl9034237
View details for Web of Science ID 000278449200002
View details for PubMedID 19891462
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Birefringence Analysis of Photonic-Bandgap Fibers Using the Hexagonal Yee's Cell
IEEE JOURNAL OF QUANTUM ELECTRONICS
2010; 46 (6): 920-930
View details for DOI 10.1109/JQE.2010.2040369
View details for Web of Science ID 000275367900004
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Combining radiationless interference with evanescent field amplification
OPTICS LETTERS
2010; 35 (10): 1659-1661
Abstract
The conventional approach for radiationless interference exploits the interference of evanescent components for the purpose of deep-subwavelength focusing and image formation. As a result, deep subwavelength feature size is achieved at the price of severe exponential decay of the field strength. We propose to overcome the limitation of the conventional approach by combining radiationless interference with evanescent field amplification as provided by the surface polaritons at the interface between positive- and negative-dielectric materials. Our approach removes the exponential decay and, moreover, allows a much wider range of wave vectors, including both propagating and evanescent field components, to participate in the image-formation process.
View details for Web of Science ID 000277773400056
View details for PubMedID 20479841
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Temporal Coupled-Mode Theory for Fano Resonance in Light Scattering by a Single Obstacle
JOURNAL OF PHYSICAL CHEMISTRY C
2010; 114 (16): 7324-7329
View details for DOI 10.1021/jp9089722
View details for Web of Science ID 000276889300018
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Thermal Rectification through Vacuum
PHYSICAL REVIEW LETTERS
2010; 104 (15)
Abstract
We propose a mechanism for photon mediated thermal rectification through vacuum relying only on the temperature dependence of electromagnetic resonances. We also propose an example implementation consisting of two polytypes of silicon carbide, which exploits the interaction of temperature dependent surface phonon polaritons to achieve significant rectification.
View details for DOI 10.1103/PhysRevLett.104.154301
View details for Web of Science ID 000277001700021
View details for PubMedID 20481993
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Enhancement of optical absorption in thin-film organic solar cells through the excitation of plasmonic modes in metallic gratings
APPLIED PHYSICS LETTERS
2010; 96 (13)
View details for DOI 10.1063/1.3377791
View details for Web of Science ID 000276275300059
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Phase front design with metallic pillar arrays
OPTICS LETTERS
2010; 35 (6): 844-846
Abstract
We demonstrate numerically, using a three-dimensional finite-difference frequency-domain method, the ability to design a phase front using an array of metallic pillars. We show that in such structures, the local phase delay upon transmission can be tuned by local geometry. We apply this knowledge to demonstrate a metallic microlens. The presented design principles apply to a wider range of wavelength-size integrated photonic components.
View details for Web of Science ID 000275827000017
View details for PubMedID 20237618
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Transmission Through a Scalar Wave Three-Dimensional Electromagnetic Metamaterial and the Implication for Polarization Control
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
2010; 10 (3): 1737-1740
Abstract
An interweaving-conductor metamaterial (ICM) is a metamaterial composed of multiple, interlocking, conducting networks. It exhibits unusual optical properties in the low-frequency linear-dispersion regime. In particular, two-network ICM supports only one, non-dispersive mode in the low frequency range, and is best described as an effective medium supporting a scalar wave in full three dimensions. We explore the light transmission properties of such a metamaterial, and the implications of a scalar wave medium for polarization control. Polarizers and polarization rotators with subwavelength sizes are numerically demonstrated.
View details for DOI 10.1166/jnn.2010.2036
View details for Web of Science ID 000273984800036
View details for PubMedID 20355567
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Multiplexed Five-Color Molecular Imaging of Cancer Cells and Tumor Tissues with Carbon Nanotube Raman Tags in the Near-Infrared
NANO RESEARCH
2010; 3 (3): 222-233
Abstract
Single-walled carbon nanotubes (SWNTs) with five different C13/C12 isotope compositions and well-separated Raman peaks have been synthesized and conjugated to five targeting ligands in order to impart molecular specificity. Multiplexed Raman imaging of live cells has been carried out by highly specific staining of cells with a five-color mixture of SWNTs. Ex vivo multiplexed Raman imaging of tumor samples uncovers a surprising up-regulation of epidermal growth factor receptor (EGFR) on LS174T colon cancer cells from cell culture to in vivo tumor growth. This is the first time five-color multiplexed molecular imaging has been performed in the near-infrared (NIR) region under a single laser excitation. Near zero interfering background of imaging is achieved due to the sharp Raman peaks unique to nanotubes over the low, smooth autofluorescence background of biological species.
View details for DOI 10.1007/s12274-010-1025-1
View details for Web of Science ID 000275754900008
View details for PubMedCentralID PMC3062899
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Mapping local optical densities of states in silicon photonic structures with nanoscale electron spectroscopy
PHYSICAL REVIEW B
2010; 81 (11)
View details for DOI 10.1103/PhysRevB.81.113102
View details for Web of Science ID 000276248800002
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Integrated Nonmagnetic Optical Isolators Based on Photonic Transitions
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2010; 16 (2): 459-466
View details for DOI 10.1109/JSTQE.2009.2026914
View details for Web of Science ID 000276418100015
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Photonic Band Structure of Dispersive Metamaterials Formulated as a Hermitian Eigenvalue Problem
PHYSICAL REVIEW LETTERS
2010; 104 (8)
Abstract
We formulate the photonic band structure calculation of any lossless dispersive photonic crystal and optical metamaterial as a Hermitian eigenvalue problem. We further show that the eigenmodes of such lossless systems provide an orthonormal basis, which can be used to rigorously describe the behavior of lossy dispersive systems in general.
View details for DOI 10.1103/PhysRevLett.104.087401
View details for Web of Science ID 000275060000043
View details for PubMedID 20366963
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Semiconductor Nanowire Optical Antenna Solar Absorbers
NANO LETTERS
2010; 10 (2): 439-445
Abstract
Photovoltaic (PV) cells can serve as a virtually unlimited clean source of energy by converting sunlight into electrical power. Their importance is reflected in the tireless efforts that have been devoted to improving the electrical and structural properties of PV materials. More recently, photon management (PM) has emerged as a powerful additional means to boost energy conversion efficiencies. Here, we demonstrate an entirely new PM strategy that capitalizes on strong broad band optical antenna effects in one-dimensional semiconductor nanostructures to dramatically enhance absorption of sunlight. We show that the absorption of sunlight in Si nanowires (Si NWs) can be significantly enhanced over the bulk. The NW's optical properties also naturally give rise to an improved angular response. We propose that by patterning the silicon layer in a thin film PV cell into an array of NWs, one can boost the absorption for solar radiation by 25% while utilizing less than half of the semiconductor material (250% increase in the light absorption per unit volume of material). These results significantly advance our understanding of the way sunlight is absorbed by one-dimensional semiconductor nanostructures and provide a clear, intuitive guidance for the design of efficient NW solar cells. The presented approach is universal to any semiconductor and a wide range of nanostructures; as such, it provides a new PV platform technology.
View details for DOI 10.1021/nl9036627
View details for Web of Science ID 000274338800013
View details for PubMedID 20078065
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NANOPHOTONICS Magnet-controlled plasmons
NATURE PHOTONICS
2010; 4 (2): 76-77
View details for DOI 10.1038/nphoton.2009.280
View details for Web of Science ID 000275058600008
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Measurement of reduced backscattering noise in laser-driven fiber optic gyroscopes
OPTICS LETTERS
2010; 35 (2): 121-123
Abstract
We report what we believe to be the first demonstration of a laser-driven fiber optic gyroscope (FOG) built with an air-core fiber. Its phase noise is measured to be 130 murad/ radicalHz. When the sensing fiber is replaced with a conventional fiber, this figure drops to 12 murad/ radicalHz. Comparison between these values suggests that the air-core fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core fiber loss to its theoretical limit (approximately 0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.
View details for Web of Science ID 000273879200010
View details for PubMedID 20081941
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Optical resonances created by photonic transitions
APPLIED PHYSICS LETTERS
2010; 96 (1)
View details for DOI 10.1063/1.3279130
View details for Web of Science ID 000273473200008
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Directional Photofluidization Lithography for Nanoarchitectures with Controlled Shapes and Sizes
NANO LETTERS
2010; 10 (1): 296-304
Abstract
Highly ordered metallic nanostructures have attracted an increasing interest in nanoscale electronics, photonics, and spectroscopic imaging. However, methods typically used for fabricating metallic nanostructures, such as direct writing and template-based nanolithography, have low throughput and are, moreover, limited to specific fabricated shapes such as holes, lines, and prisms, respectively. Herein, we demonstrate directional photofluidization lithography (DPL) as a new method to address the aforementioned problems of current nanolithography. The key idea of DPL is the use of photoreconfigurable polymer arrays to be molded in metallic nanostructures instead of conventional colloids or cross-linked polymer arrays. The photoreconfiguration of polymers by directional photofluidization allows unprecedented control over the sizes and shapes of metallic nanostructures. Besides the capability for precise control of structural features, DPL ensures scalable, parallel, and cost-effective processing, highly compatible with high-throughput fabrication. Therefore, DPL can expand not only the potential for specific metallic nanostructure applications but also large-scale innovative nanolithography.
View details for DOI 10.1021/nl903570c
View details for Web of Science ID 000273428700050
View details for PubMedID 20017565
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Magnetic field enhancement beyond the skin-depth limit
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.841805
View details for Web of Science ID 000285577600011
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Slow and Stopped Light in Coupled Resonator Systems
PHOTONIC MICRORESONATOR RESEARCH AND APPLICATIONS
2010; 156: 165-180
View details for DOI 10.1007/978-1-4419-1744-7_7
View details for Web of Science ID 000278855600007
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Enhancement of optics-to-THz conversion efficiency by metallic slot waveguides
Conference on Nonlinear Frequency Generation and Conversion - Materials, Devices, and Applications IX
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.840088
View details for Web of Science ID 000284935000027
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DESIGN AND GROWTH OF III-V NANOWIRE SOLAR CELL ARRAYS ON LOW COST SUBSTRATES
35th IEEE Photovoltaic Specialists Conference
IEEE. 2010: 2034–2037
View details for Web of Science ID 000287579502062
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Transparent electrode designs based on optimal nano-patterning of metallic films
Conference on Plasmonics: Metallic Nanostructures and Their Optical Properties VIII
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.860998
View details for Web of Science ID 000285828300028
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Coupled resonator gyroscopes: what works and what does not
Conference on Advances in Slow and Fast Light III
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.848637
View details for Web of Science ID 000284309300006
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Suspended photonic crystal slabs for biosensing
Conference On Frontiers in Pathogen Detection - From Nanosensors to Systems
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.842945
View details for Web of Science ID 000285577200016
- Absorber and emitter for solar thermophotovoltaic systems to achieve efficiency exceeding the Shockley-Queisser limit Optics Express 2010; 17 (17): 15145-15159
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Full inversion of a two-level atom with a single-photon pulse in one-dimensional geometries
Physical Review A
2010; 82 (3)
View details for DOI 033804 10.1103/PhysRevA.82.033804
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Experimental demonstration of an all-optical analogue to the superradiance effect in an on-chip photonic crystal resonator system
Physical Review B
2010; 81 (4)
View details for DOI 041101 10.1103/PhysRevB.81.041101
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Exponential suppression of thermal conductance using coherent transport and heterostructures
Physical Review B
2010; 82 (11)
View details for DOI 113105 10.1103/PhysRevB.82.113105
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Enhancement of optical absorption in thin-film organic solar cells through the excitation of plasmonic modes in metallic gratings
Applied Physics Letters
2010; 96 (13)
View details for DOI 133302 10.1063/1.3377791
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Tuning the coherent interaction in an on-chip photonic-crystal waveguide-resonator system
Applied Physics Letters
2010; 97 (10)
View details for DOI 101102 10.1063/1.3486686
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Input-output formalism for few-photon transport in one-dimensional nanophotonic waveguides coupled to a qubit
Physical Review A
2010; 82 (6)
View details for DOI 063821 10.1103/PhysRevA.82.063821
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Thermal Rectification through Vacuum
Physical Review Letters
2010; 104 (15)
View details for DOI 154301 10.1103/PhysRevLett.104.154301
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Superscattering of Light from Subwavelength Nanostructures
Physical Review Letters
2010; 105 (1)
View details for DOI 013901 10.1103/PhysRevLett.105.013901
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Elements for Plasmonic Nanocircuits with Three-Dimensional Slot Waveguides
Advanced Materials
2010; 22 (45): 5120-+
View details for DOI 10.1002/adma.201001440
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Quantum critical coupling conditions for zero single-photon transmission through a coupled atom-resonator-waveguide system
Physical Review A
2010; 82 (2)
View details for DOI 021802 10.1103/PhysRevA.82.021802
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Photonic Band Structure of Dispersive Metamaterials Formulated as a Hermitian Eigenvalue Problem
Physical Review Letters
2010; 104 (8)
View details for DOI 087401 10.1103/PhysRevLett.104.087401
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Optical resonances created by photonic transitions
Applied Physics Letters
2010; 96 (1)
View details for DOI 011108 10.1063/1.3279130
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Mapping local optical densities of states in silicon photonic structures with nanoscale electron spectroscopy
Physical Review B
2010; 81 (11)
View details for DOI 113102 10.1103/PhysRevB.81.113102
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Enhancing optical switching with coherent control
Applied Physics Letters
2010; 96 (23)
View details for DOI 231108 10.1063/1.3449572
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Deep-subwavelength focusing and steering of light in an aperiodic metallic waveguide array
Conference on Integrated Optics - Devices, Materials, and Technologies XIV
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.842692
View details for Web of Science ID 000284398000020
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Optimizing Nano-patterned Metal Films for Use as Transparent Electrodes in Optoelectronic Devices
Conference on Lasers and Electro-Optics (CLEO)/Quantum Electronics and Laser Science Conference (QELS)
IEEE. 2010
View details for Web of Science ID 000290513603066
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Dynamic Photonic Structure for Integrated Photonics
Conference on Optoelectronic Integrated Circuits XII
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.846032
View details for Web of Science ID 000284396700018
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LIMIT OF NANOPHOTONIC LIGHT-TRAPPING IN SOLAR CELLS
35th IEEE Photovoltaic Specialists Conference
IEEE. 2010: 76–78
View details for Web of Science ID 000287579500016
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Fundamental Limit of Nanophotonic Light-trapping in Solar Cells
Conference on Lasers and Electro-Optics (CLEO)/Quantum Electronics and Laser Science Conference (QELS)
IEEE. 2010
View details for Web of Science ID 000290513600264
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Phase Front Design with Metallic Pillar Arrays
Conference on Lasers and Electro-Optics (CLEO)/Quantum Electronics and Laser Science Conference (QELS)
IEEE. 2010
View details for Web of Science ID 000290513603159
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Temporal coupled-mode theory for the Fano resonance in light scattering and its applications
Conference on Lasers and Electro-Optics (CLEO)/Quantum Electronics and Laser Science Conference (QELS)
IEEE. 2010
View details for Web of Science ID 000290513603080
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Fundamental Limit of Nanophotonic Light-trapping in Solar Cells
Conference on Next Generation (Nano) Photonic and Cell Technologies for Solar Energy Conversion
SPIE-INT SOC OPTICAL ENGINEERING. 2010
View details for DOI 10.1117/12.861457
View details for Web of Science ID 000285841900015
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Experimental demonstration of an all-optical analogue to the superradiance effect in an on-chip photonic crystal resonator system
PHYSICAL REVIEW B
2010; 81 (4)
View details for DOI 10.1103/PhysRevB.81.041101
View details for Web of Science ID 000274002500001
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Resonance-enhanced optical forces between coupled photonic crystal slabs
OPTICS EXPRESS
2009; 17 (24): 21897-21909
Abstract
The behaviors of lateral and normal optical forces between coupled photonic crystal slabs are analyzed. We show that the optical force is periodic with displacement, resulting in stable and unstable equilibrium positions. Moreover, the forces are strongly enhanced by guided resonances of the coupled slabs. Such enhancement is particularly prominent near dark states of the system, and the enhancement effect is strongly dependent on the types of guided resonances involved. These structures lead to enhancement of light-induced pressure over larger areas, in a configuration that is directly accessible to externally incident, free-space optical beams.
View details for Web of Science ID 000272229400061
View details for PubMedID 19997434
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Two-electron transport in a quantum waveguide having a single Anderson impurity
NEW JOURNAL OF PHYSICS
2009; 11
View details for DOI 10.1088/1367-2630/11/11/113024
View details for Web of Science ID 000271649200009
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Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna
NATURE PHOTONICS
2009; 3 (11): 654-657
View details for DOI 10.1038/NPHOTON.2009.187
View details for Web of Science ID 000272302700012
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Universal features of coherent photonic thermal conductance in multilayer photonic band gap structures
PHYSICAL REVIEW B
2009; 80 (15)
View details for DOI 10.1103/PhysRevB.80.155135
View details for Web of Science ID 000271352000068
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Wave-vector space picture for radiationless focusing and beaming
OPTICS LETTERS
2009; 34 (19): 2967-2969
Abstract
Radiationless interference of an electromagnetic wave occurs in the near field when the feature sizes of the waves are at the deep subwavelength scale. We present the propagation in such a regime using a wave-vector space picture. Using this picture, we reproduce the condition to achieve near-field focusing. We also design the initial field distribution needed for near-field beaming, where an intensity distribution maintains its shape as it propagates. We conclude the discussion by proposing a possible implementation of the near-field beaming scheme.
View details for Web of Science ID 000270366800030
View details for PubMedID 19794784
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Side-coupled cavity model for surface plasmon-polariton transmission across a groove
OPTICS EXPRESS
2009; 17 (20): 17837-17848
Abstract
We demonstrate that the transmission properties of surface plasmon-polaritons (SPPs) across a rectangular groove in a metallic film can be described by an analytical model that treats the groove as a side-coupled cavity to propagating SPPs on the metal surface. The coupling efficiency to the groove is quantified by treating it as a truncated metal-dielectric-metal (MDM) waveguide. Finite-difference frequency-domain (FDFD) simulations and mode orthogonality relations are employed to derive the basic scattering coefficients that describe the interaction between the relevant modes in the system. The modeled SPP transmission and reflection intensities show excellent agreement with full-field simulations over a wide range of groove dimensions, validating this intuitive model. The model predicts the sharp transmission minima that occur whenever an incident SPP resonantly couples to the groove. We also for the first time show the importance of evanescent, reactive MDM SPP modes to the transmission behavior. SPPs that couple to this mode are resonantly enhanced upon reflection from the bottom of the groove, leading to high field intensities and sharp transmission minima across the groove. The resonant behavior exhibited by the grooves has a number of important device applications, including SPP mirrors, filters, and modulators.
View details for Web of Science ID 000270295300065
View details for PubMedID 19907571
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Ring-coupled Mach-Zehnder interferometer optimized for sensing
APPLIED OPTICS
2009; 48 (26): 4874-4879
Abstract
We demonstrate numerically that the theoretical maximum sensitivity of a ring-coupled Mach-Zehnder interferometer (MZI) optimized as a sensor is about 30% greater than the optimized sensitivity of a conventional single-bus ring sensor with an identical ring perimeter and loss. The ring-coupled MZI sensor also achieves its greater sensitivity with a 25% lower circulating power, which is useful for the suppression of undesirable nonlinear effects.
View details for Web of Science ID 000270117600004
View details for PubMedID 19745847
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Classification of the Core Modes of Hollow-Core Photonic-Bandgap Fibers
IEEE JOURNAL OF QUANTUM ELECTRONICS
2009; 45 (9): 1192-1200
View details for DOI 10.1109/JQE.2009.2019767
View details for Web of Science ID 000269389600001
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Performance comparison of slow-light coupled-resonator optical gyroscopes
LASER & PHOTONICS REVIEWS
2009; 3 (5): 452-465
View details for DOI 10.1002/lpor.200810052
View details for Web of Science ID 000269922000003
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Overcoming gain-bandwidth product constraint in slow light Raman amplification with the use of light-stopping schemes
APPLIED PHYSICS LETTERS
2009; 95 (8)
View details for DOI 10.1063/1.3211126
View details for Web of Science ID 000269723200003
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Planar metallic nanoscale slit lenses for angle compensation
APPLIED PHYSICS LETTERS
2009; 95 (7)
View details for DOI 10.1063/1.3211875
View details for Web of Science ID 000269288300012
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Absorber and emitter for solar thermophotovoltaic systems to achieve efficiency exceeding the Shockley-Queisser limit
OPTICS EXPRESS
2009; 17 (17): 15145-15159
Abstract
We present theoretical considerations as well as detailed numerical design of absorber and emitter for Solar Thermophotovoltaics (STPV) applications. The absorber, consisting of an array of tungsten pyramids, was designed to provide near-unity absorptivity over all solar wavelengths for a wide angular range, enabling it to absorb light effectively from solar sources regardless of concentration. The emitter, a tungsten slab with Si/SiO(2) multilayer stack, provides a sharp emissivity peak at the solar cell band-gap while suppressing emission at lower frequencies. We show that, under a suitable light concentration condition, and with a reasonable area ratio between the emitter and absorber, a STPV system employing such absorber-emitter pair and a single-junction solar cell can attain efficiency that exceeds the Shockley-Queisser limit.
View details for Web of Science ID 000269232800069
View details for PubMedID 19687992
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Enhancement of optics-to-THz conversion efficiency by metallic slot waveguides
OPTICS EXPRESS
2009; 17 (16): 13502-13515
Abstract
A metallic slot waveguide, with a dielectric strip embedded within, is investigated for the purpose of enhancing the optics-to-THz conversion efficiency using the difference-frequency generation (DFG) process. To describe the frequency conversion process in such lossy waveguides, a fully-vectorial coupled-mode theory is developed. Using the coupled-mode theory, we outline the basic theoretical requirements for efficient frequency conversion, which include the needs to achieve large coupling coefficients, phase matching, and low propagation loss for both the optical and THz waves. Following these requirements, a metallic waveguide is designed by considering the trade-off between modal confinement and propagation loss. Our numerical calculation shows that the conversion efficiency in these waveguide structures can be more than one order of magnitude larger than what has been achieved using dielectric waveguides. Based on the distinct impact of the slot width on the optical and THz modal dispersion, we propose a two-step method to realize the phase matching for general pump wavelengths.
View details for Web of Science ID 000268843700027
View details for PubMedID 19654758
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Modeling of Plasmonic Waveguide Components and Networks
JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE
2009; 6 (8): 1808-1826
View details for DOI 10.1166/jctn.2009.1244
View details for Web of Science ID 000269887100006
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Measurements of the Birefringence and Verdet Constant in an Air-Core Fiber
JOURNAL OF LIGHTWAVE TECHNOLOGY
2009; 27 (15): 3194-3201
View details for DOI 10.1109/JLT.2008.2009546
View details for Web of Science ID 000268284200010
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Deep-Subwavelength Focusing and Steering of Light in an Aperiodic Metallic Waveguide Array
PHYSICAL REVIEW LETTERS
2009; 103 (3)
Abstract
We consider an aperiodic array of coupled metallic waveguides with varying subwavelength widths. For an incident plane wave, we numerically demonstrate that a focus of as small as one-hundredth of a wavelength can be achieved for a focal distance that is much longer than the wavelength. Moreover, the focusing behavior can be controlled by changing either the incident wavelength or the angle of incidence, thus providing the capability of nanoscale beam steering. We show that the behavior of such subwavelength focusing can be understood using Hamiltonian optics.
View details for DOI 10.1103/PhysRevLett.103.033902
View details for Web of Science ID 000268088300027
View details for PubMedID 19659280
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Understanding the dispersion of coaxial plasmonic structures through a connection with the planar metal-insulator-metal geometry
APPLIED PHYSICS LETTERS
2009; 94 (23)
View details for DOI 10.1063/1.3148692
View details for Web of Science ID 000266977100011
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Capturing light pulses into a pair of coupled photonic crystal cavities
APPLIED PHYSICS LETTERS
2009; 94 (23)
View details for DOI 10.1063/1.3141485
View details for Web of Science ID 000266977100009
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Optical isolation based on nonreciprocal phase shift induced by interband photonic transitions
APPLIED PHYSICS LETTERS
2009; 94 (17)
View details for DOI 10.1063/1.3127531
View details for Web of Science ID 000265738700016
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Three-Dimensional Metamaterials with an Ultrahigh Effective Refractive Index over a Broad Bandwidth
PHYSICAL REVIEW LETTERS
2009; 102 (9)
Abstract
The authors introduce a general mechanism, based on electrostatic and magnetostatic considerations, for designing three-dimensional isotropic metamaterials that possess an enhanced refractive index over an extremely large frequency range. The mechanism allows nearly independent control of effective electric permittivity and magnetic permeability without the use of resonant elements.
View details for DOI 10.1103/PhysRevLett.102.093903
View details for Web of Science ID 000263911900022
View details for PubMedID 19392520
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Extraordinary optical absorption through subwavelength slits
OPTICS LETTERS
2009; 34 (5): 686-688
Abstract
We report on the ability of resonant plasmonic slits to efficiently concentrate electromagnetic energy into a nanoscale volume of absorbing material placed inside or directly behind the slit. This gives rise to extraordinary optical absorption characterized by an absorption enhancement factor that well exceeds the enhancements seen for extraordinary optical transmission through slits. A semianalytic Fabry-Perot model for the resonant absorption is developed and shown to quantitatively agree with full-field simulations. We show that absorption enhancements of nearly 1000% can be realized at 633 nm for slits in aluminum films filled with silicon. This effect can be utilized in a wide range of applications, including high-speed photodetectors, optical lithography and recording, and biosensors.
View details for Web of Science ID 000264522400046
View details for PubMedID 19252593
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Complete optical isolation created by indirect interband photonic transitions
NATURE PHOTONICS
2009; 3 (2): 91-94
View details for DOI 10.1038/NPHOTON.2008.273
View details for Web of Science ID 000263181100012
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Theory of single-photon transport in a single-mode waveguide. II. Coupling to a whispering-gallery resonator containing a two-level atom
PHYSICAL REVIEW A
2009; 79 (2)
View details for DOI 10.1103/PhysRevA.79.023838
View details for Web of Science ID 000263815000176
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Theory of single-photon transport in a single-mode waveguide. I. Coupling to a cavity containing a two-level atom
PHYSICAL REVIEW A
2009; 79 (2)
View details for DOI 10.1103/PhysRevA.79.023837
View details for Web of Science ID 000263815000175
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Optical Absorption Enhancement in Amorphous Silicon Nanowire and Nanocone Arrays
NANO LETTERS
2009; 9 (1): 279-282
Abstract
Hydrogenated amorphous Si (a-Si:H) is an important solar cell material. Here we demonstrate the fabrication of a-Si:H nanowires (NWs) and nanocones (NCs), using an easily scalable and IC-compatible process. We also investigate the optical properties of these nanostructures. These a-Si:H nanostructures display greatly enhanced absorption over a large range of wavelengths and angles of incidence, due to suppressed reflection. The enhancement effect is particularly strong for a-Si:H NC arrays, which provide nearly perfect impedance matching between a-Si:H and air through a gradual reduction of the effective refractive index. More than 90% of light is absorbed at angles of incidence up to 60 degrees for a-Si:H NC arrays, which is significantly better than NW arrays (70%) and thin films (45%). In addition, the absorption of NC arrays is 88% at the band gap edge of a-Si:H, which is much higher than NW arrays (70%) and thin films (53%). Our experimental data agree very well with simulation. The a-Si:H nanocones function as both absorber and antireflection layers, which offer a promising approach to enhance the solar cell energy conversion efficiency.
View details for DOI 10.1021/nl802886y
View details for Web of Science ID 000262519100052
View details for PubMedID 19072061
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Stopping Light via Dynamic Tuning of Coupled Resonators
SLOW LIGHT: SCIENCE AND APPLICATIONS
2009; 140: 277-289
View details for Web of Science ID 000267161300014
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PLASMONIC SLOT WAVEGUIDES
PLASMONIC NANOGUIDES AND CIRCUITS
2009: 159-187
View details for Web of Science ID 000289061900007
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Complete optical isolation created by indirect interband photonic transitions
Conference on Silicon Photonics IV
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.807739
View details for Web of Science ID 000285748000022
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Ultra-Small Coherent Thermal Conductance Using Multi-Layer Photonic Crystal
Conference on Photonic and Phononic Crystal Materials and Devices IX
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.808432
View details for Web of Science ID 000285746400022
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Coupled resonator optical waveguide sensors: sensitivity and the role of slow light
Conference on Fiber Optic Sensors and Applications VI
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.833477
View details for Web of Science ID 000299088400016
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Large enhancement of second-harmonic generation in subwavelength metal-dielectric-metal plasmonic waveguides
Conference on Integrated Optics - Devices, Materials, and Technologies XIII
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.809727
View details for Web of Science ID 000285748100025
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Theory of single-photon transport in a single-mode waveguide. II. Coupling to a whispering-gallery resonator containing a two-level atom
Physical Review A
2009; 79 (2)
View details for DOI 023838 10.1103/PhysRevA.79.023838
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Overcoming gain-bandwidth product constraint in slow light Raman amplification with the use of light-stopping schemes
Applied Physics Letters
2009; 95 (8)
View details for DOI 081103 10.1063/1.3211126
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Two-electron transport in a quantum waveguide having a single Anderson impurity
New Journal of Physics
2009; 11
View details for DOI 113024 10.1088/1367-2630/11/11/113024
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Planar metallic nanoscale slit lenses for angle compensation
Applied Physics Letters
2009; 95 (7)
View details for DOI 071112 10.1063/1.3211875
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Deep-Subwavelength Focusing and Steering of Light in an Aperiodic Metallic Waveguide Array
Physical Review Letters
2009; 103 (3)
View details for DOI 033902 10.1103/PhysRevLett.103.033902
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Universal features of coherent photonic thermal conductance in multilayer photonic band gap structures
Physical Review B
2009; 80 (15)
View details for DOI 155135 10.1103/PhysRevB.80.155135
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Understanding the dispersion of coaxial plasmonic structures through a connection with the planar metal-insulator-metal geometry
Applied Physics Letters
2009; 94 (23)
View details for DOI 231111 10.1063/1.3148692
- Three-Dimensional Metamaterials with an Ultrahigh Effective Refractive Index over a Broad Bandwidth Physical Review Letters 2009; 102 (9)
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Theory of single-photon transport in a single-mode waveguide. I. Coupling to a cavity containing a two-level atom
Physical Review A
2009; 79 (2)
View details for DOI 023837 10.1103/PhysRevA.79.023837
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Optical isolation based on nonreciprocal phase shift induced by interband photonic transitions
Applied Physics Letters
2009; 94 (17)
View details for DOI 171116 10.1063/1.3127531
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Capturing light pulses into a pair of coupled photonic crystal cavities
Applied Physics Letters
2009; 94 (23)
View details for DOI 231109 10.1063/1.3141485
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Modal analysis and coupling in metal-insulator-metal waveguides
Physical Review B
2009; 79 (3)
View details for DOI 035120 10.1103/PhysRevB.79.035120
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Simple Analytical Expression for the Dispersion of Plasmonic Structures with Coaxial Geometry
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2009)
IEEE. 2009: 1838–1839
View details for Web of Science ID 000274751301244
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Integrated nanophotonics: dynamic optical isolation, and nanoscale far-field focusing in aperiodic plasmonic waveguide array
22nd Annual Meeting of the IEEE-Photonics-Society
IEEE. 2009: 646–647
View details for Web of Science ID 000279577600331
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Light Trapping With a Few Cavities
Conference on Advances in Slow and Fast Light II
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.816328
View details for Web of Science ID 000285377800018
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Performance Limitation of a Coupled Resonant Optical Waveguide Gyroscope
JOURNAL OF LIGHTWAVE TECHNOLOGY
2009; 27 (1-4): 47-54
View details for DOI 10.1109/JLT.2008.927753
View details for Web of Science ID 000263768300006
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Dynamics of optical modes in modulated photonic structures
IEEE/LEOS Winter Topicals Meeting
IEEE. 2009: 106–107
View details for Web of Science ID 000267006500055
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Optical Resonances Created by Photonic Transitions
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2009)
IEEE. 2009: 1327–1328
View details for Web of Science ID 000274751300667
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Planar Lenses Based on Nanoscale Slit Arrays in a Metallic Film
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2009)
IEEE. 2009: 3224–3225
View details for Web of Science ID 000274751302598
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Minimizing Coherent Thermal Conductance Using Multi-Layer Photonic Crystal Heterostructures
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2009)
IEEE. 2009: 2035–2036
View details for Web of Science ID 000274751301345
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Modal analysis and coupling in metal-insulator-metal waveguides
PHYSICAL REVIEW B
2009; 79 (3)
View details for DOI 10.1103/PhysRevB.79.035120
View details for Web of Science ID 000262978200055
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Planar Lenses Based on Nanoscale Slit Arrays in a Metallic Film
NANO LETTERS
2009; 9 (1): 235-238
Abstract
We experimentally demonstrate planar lenses based on nanoscale slit arrays in a metallic film. Our lens structures consist of optically thick gold films with micron-size arrays of closely spaced, nanoscale slits of varying widths milled using a focused ion beam. We find excellent agreement between electromagnetic simulations of the design and confocal measurements on manufactured structures. We provide guidelines for lens design and show how actual lens behavior deviates from simple theory.
View details for DOI 10.1021/nl802830y
View details for Web of Science ID 000262519100044
View details for PubMedID 19053795
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Analysis of guided-resonance-based polarization beam splitting in photonic crystal slabs
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
2008; 25 (11): 2680-2692
Abstract
We present an analysis of the phase and amplitude responses of guided resonances in a photonic crystal slab. Through this analysis, we obtain the general rules and conditions under which a photonic crystal slab can be employed as a general elliptical polarization beam splitter, separating an incoming beam equally into its two orthogonal constituents, so that half the power is reflected in one polarization state, and half the power is transmitted in the other state. We show that at normal incidence a photonic crystal slab acts as a dual quarter-wave retarder in which the fast and slow axes are switched for reflection and transmission. We also analyze the case where such a structure operates at oblique incidences. As a result we show that the effective dielectric constant of the photonic crystal slab imposes the Brewster angle as a boundary, separating two ranges of angles with different mechanisms of polarization beam splitting. We show that the diattenuation can be tuned from zero to one to make the structure a circular or linear polarization beam splitter. We verify our analytical analysis through finite-difference time-domain simulations and experimental measurements at infrared wavelengths.
View details for Web of Science ID 000261520700008
View details for PubMedID 18978845
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Completely Capturing Light Pulses in a Few Dynamically Tuned Microcavities
JOURNAL OF LIGHTWAVE TECHNOLOGY
2008; 26 (21-24): 3784-3793
View details for DOI 10.1109/JLT.2008.2005511
View details for Web of Science ID 000263225000033
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Protein microarrays with carbon nanotubes as multicolor Raman labels
NATURE BIOTECHNOLOGY
2008; 26 (11): 1285-1292
Abstract
The current sensitivity of standard fluorescence-based protein detection limits the use of protein arrays in research and clinical diagnosis. Here, we use functionalized, macromolecular single-walled carbon nanotubes (SWNTs) as multicolor Raman labels for highly sensitive, multiplexed protein detection in an arrayed format. Unlike fluorescence methods, Raman detection benefits from the sharp scattering peaks of SWNTs with minimal background interference, affording a high signal-to-noise ratio needed for ultra-sensitive detection. When combined with surface-enhanced Raman scattering substrates, the strong Raman intensity of SWNT tags affords protein detection sensitivity in sandwich assays down to 1 fM--a three-order-of-magnitude improvement over most reports of fluorescence-based detection. We use SWNT Raman tags to detect human autoantibodies against proteinase 3, a biomarker for the autoimmune disease Wegener's granulomatosis, diluted up to 10(7)-fold in 1% human serum. SWNT Raman tags are not subject to photobleaching or quenching. By conjugating different antibodies to pure (12)C and (13)C SWNT isotopes, we demonstrate multiplexed two-color SWNT Raman-based protein detection.
View details for DOI 10.1038/nbt.1501
View details for Web of Science ID 000260832200024
View details for PubMedID 18953353
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Transmission Line and Equivalent Circuit Models for Plasmonic Waveguide Components
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2008; 14 (6): 1462-1472
View details for DOI 10.1109/JSTQE.2008.924431
View details for Web of Science ID 000262220500008
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Multiplexed multicolor Raman imaging of live cells with isotopically modified single walled carbon nanotubes
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
2008; 130 (41): 13540-?
Abstract
We show that single walled carbon nanotubes (SWNTs) with different isotope compositions exhibit distinct Raman G-band peaks and can be used for multiplexed multicolor Raman imaging of biological systems. Cancer cells with specific receptors are selectively labeled with three differently "colored" SWNTs conjugated with various targeting ligands including Herceptin (anti-Her2), Erbitux (anti-Her1), and RGD peptide, allowing for multicolor Raman imaging of cells in a multiplexed manner. SWNT Raman signals are highly robust against photobleaching, allowing long-term imaging and tracking. With narrow peak features, SWNT Raman signals are easily differentiated from the autofluorescence background. The SWNT Raman excitation and scattering photons are in the near-infrared region, which is the most transparent optical window for biological systems in vitro and in vivo. Thus, SWNTs are novel Raman tags promising for multiplexed biological detection and imaging.
View details for DOI 10.1021/ja806242t
View details for Web of Science ID 000259924000017
View details for PubMedID 18803379
View details for PubMedCentralID PMC2617744
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Tungsten black absorber for solar light with wide angular operation range
APPLIED PHYSICS LETTERS
2008; 92 (21)
View details for DOI 10.1063/1.2936997
View details for Web of Science ID 000256303500007
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Aligning microcavity resonances in silicon photonic-crystal slabs using laser-pumped thermal tuning
APPLIED PHYSICS LETTERS
2008; 92 (10)
View details for DOI 10.1063/1.2896615
View details for Web of Science ID 000253989300114
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Tuning coherent radiative thermal conductance in multilayer photonic crystals
APPLIED PHYSICS LETTERS
2008; 92 (10)
View details for DOI 10.1063/1.2890433
View details for Web of Science ID 000253989300106
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Crosstalk between three-dimensional plasmonic slot waveguides
OPTICS EXPRESS
2008; 16 (3): 2129-2140
Abstract
We investigate in detail the crosstalk between plasmonic slot waveguides. We show that the coupling behavior of deep subwavelength three-dimensional (3-D) plasmonic slot waveguides is very different from the one of two-dimensional (2-D) metal-dielectric-metal (MDM) plasmonic waveguides. While in the 2-D case the coupling occurs only through the metal, in the 3-D case the coupling occurs primarily through the dielectric, in which the evanescent tail is much larger compared to the one in the metal. Thus, in most cases the coupling between 3-D plasmonic slot waveguides is much stronger than the coupling between the corresponding 2-D MDM plasmonic waveguides. Such strong coupling can be exploited to form directional couplers using plasmonic slot waveguides. On the other hand, with appropriate design, the crosstalk between 3-D plasmonic slot waveguides can be reduced even below the crosstalk levels of 2-D MDM plasmonic waveguides, without significantly affecting their modal size and attenuation length. Thus, 3-D plasmonic slot waveguides can be used for ultradense integration of optoelectronic components.
View details for Web of Science ID 000252932500081
View details for PubMedID 18542293
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Gain-induced switching in metal-dielectric-metal plasmonic waveguides
APPLIED PHYSICS LETTERS
2008; 92 (4)
View details for DOI 10.1063/1.2839324
View details for Web of Science ID 000252860400017
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One-way electromagnetic waveguide formed at the interface between a plasmonic metal under a static magnetic field and a photonic crystal
PHYSICAL REVIEW LETTERS
2008; 100 (2)
Abstract
We demonstrate theoretically the existence of one-way electromagnetic modes in a waveguide formed between a semi-infinite photonic crystal structure and a semi-infinite metal region under a static magnetic field. Such a waveguide provides a frequency range where only one propagating direction is allowed. In this frequency range, disorder-induced scattering is completely suppressed. Such a waveguide also modifies the basic properties of waveguide-cavity interaction.
View details for DOI 10.1103/PhysRevLett.100.023902
View details for Web of Science ID 000252471200031
View details for PubMedID 18232868
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GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector
APPLIED PHYSICS LETTERS
2008; 92 (1)
View details for DOI 10.1063/1.2831716
View details for Web of Science ID 000252284200029
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Tuning Coherent Radiative Thermal Conductance in Multilayer Photonic Crystals
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2008)
IEEE. 2008: 3026–3027
View details for Web of Science ID 000260498401505
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Photonic crystal theory: Temporal coupled-mode formalism
OPTICAL FIBER TELECOMMUNICATIONS V A: COMPONENTS AND SUBSYSTEMS
2008: 431-454
View details for DOI 10.1016/B978-0-12-374171-4.00012-5
View details for Web of Science ID 000317293700012
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Gain-induced switching in metal-dielectric-metal plasmonic waveguides
SPIE-INT SOC OPTICAL ENGINEERING. 2008
View details for DOI 10.1117/12.764052
View details for Web of Science ID 000254226600016
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Properties of three-dimensional plasmonic slot waveguides
Conference on Plasmonics - Metallic Nanostructures and their Optical Properties VI
SPIE-INT SOC OPTICAL ENGINEERING. 2008
View details for DOI 10.1117/12.794322
View details for Web of Science ID 000260664900015
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Spatial coherence of the thermal electromagnetic field in the vicinity of a dielectric slab
Conference on Photonic Crystal Materials and Devices VII
SPIE-INT SOC OPTICAL ENGINEERING. 2008
View details for DOI 10.1117/12.761909
View details for Web of Science ID 000254740000003
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Fabrication and Performance of GaN-based Two Dimensional Photonic Crystal Surface Emitting Lasers
IEEE 21st International Semiconductor Laser Conference
IEEE. 2008: 187–188
View details for Web of Science ID 000263222600094
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Tungsten black absorber for solar light with wide angular operation range
Applied Physics Letters
2008; 92 (21)
View details for DOI 211107 10.1063/1.2936997
-
Propagating plasmonic mode in nanoscale apertures and its implications for extraordinary transmission
Journal of Nanophotonics
2008; 2
View details for DOI 021790 10.1117/1.2890424
-
Gain-induced switching in metal-dielectric-metal plasmonic waveguides
Applied Physics Letters
2008; 92 (4)
View details for DOI 041117 10.1063/1.2839324
-
GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector
Applied Physics Letters
2008; 92 (1)
View details for DOI 011129 10.1063/1.2831716
-
Aligning microcavity resonances in silicon photonic-crystal slabs using laser-pumped thermal tuning
Applied Physics Letters
2008; 92 (10)
View details for DOI 103114 10.1063/1.2896615
-
One-way electromagnetic waveguide formed at the interface between a plasmonic metal under a static magnetic field and a photonic crystal
Physical Review Letters
2008; 100 (2)
View details for DOI 023902 10.1103/PhysRevLett.100.023902
-
Tuning coherent radiative thermal conductance in multilayer photonic crystals
Applied Physics Letters
2008; 92 (10)
View details for DOI 103106 10.1063/1.2890433
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Stopping and time-reversing a light pulse using dynamic loss-tuning of coupled-resonator delay lines
Conference on Laser Resonators and Beam Control X
SPIE-INT SOC OPTICAL ENGINEERING. 2008
View details for DOI 10.1117/12.773815
View details for Web of Science ID 000255510400011
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Crosstalk between three-dimensional plasmonic slot waveguides
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2008)
IEEE. 2008: 3571–3572
View details for Web of Science ID 000260498401781
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Deep-Subwavelength Coaxial Waveguides with a Hollow Core
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2008)
IEEE. 2008: 3567–3568
View details for Web of Science ID 000260498401779
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Propagating plasmonic mode in nanoscale apertures and its implications for extraordinary transmission
JOURNAL OF NANOPHOTONICS
2008; 2
View details for DOI 10.1117/1.2890424
View details for Web of Science ID 000262931600013
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Dispersionless Three-dimensional Metamaterial with a Very High Refractive Index
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2008)
IEEE. 2008: 3131–3132
View details for Web of Science ID 000260498401559
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Strongly correlated multiparticle transport in one dimension through a quantum impurity
PHYSICAL REVIEW A
2007; 76 (6)
View details for DOI 10.1103/PhysRevA.76.062709
View details for Web of Science ID 000251985900067
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Stopping and time reversing a light pulse using dynamic loss tuning of coupled-resonator delay lines
OPTICS LETTERS
2007; 32 (22): 3333-3335
Abstract
We introduce a light-stopping process that uses dynamic loss tuning in coupled-resonator delay lines. We demonstrate via numerical simulations that increasing the loss of selected resonators traps light in a zero group velocity mode concentrated in the low-loss portions of the delay line. The large dynamic range achievable for loss modulation should increase the light-stopping bandwidth relative to previous approaches based on refractive index tuning.
View details for Web of Science ID 000251747600037
View details for PubMedID 18026298
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Enlarging the bandwidth of nanoscale propagating plasmonic modes in deep-subwavelength cylindrical holes
APPLIED PHYSICS LETTERS
2007; 91 (18)
View details for DOI 10.1063/1.2803849
View details for Web of Science ID 000250643600018
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Three-dimensional electromagnetic metamaterials that homogenize to uniform non-Maxwellian media
PHYSICAL REVIEW B
2007; 76 (11)
View details for DOI 10.1103/PhysRevB.76.113101
View details for Web of Science ID 000249786400001
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Modes of subwavelength plasmonic slot waveguides
JOURNAL OF LIGHTWAVE TECHNOLOGY
2007; 25 (9): 2511-2521
View details for DOI 10.1109/JLT.2007.903544
View details for Web of Science ID 000249350000030
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The nonlinear effect from the interplay between the nonlinearity and the supercollimation of photonic crystal
APPLIED PHYSICS LETTERS
2007; 91 (3)
View details for DOI 10.1063/1.2739413
View details for Web of Science ID 000248194000005
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Spatial coherence of the thermal electromagnetic field in the vicinity of a dielectric slab
PHYSICAL REVIEW E
2007; 76 (1)
Abstract
We present the analytic calculation of the cross-spectral density tensor of a thermally radiative planar dielectric slab in extreme near-field, intermediate near-field, and far-field zones. We show that the spatial coherence of the thermal field exhibits distinct features in these zones. At a given wavelength lambda , the coherence length is many orders of magnitude smaller than lambda in the extreme near-field zone, and is roughly lambda/2 in the far-field zone. In the intermediate near-field zone, the coherence length can be much longer than lambda/2 if the loss is small. The physical origin of the short-ranged spatial coherence in the extreme near-field zone is the spatially fluctuating surface charges at the air-dielectric interface. We also demonstrate that in the intermediate near-field zone, the long-ranged spatial coherence is induced by the waveguide modes of the dielectric slab. When the loss is small, the long-ranged coherence falls off approximately as 1/square root x , in contrast to 1/x for a blackbody radiator, where x refers to displacement parallel to the slab surface.
View details for DOI 10.1103/PhysRevE.76.016601
View details for Web of Science ID 000248552600058
View details for PubMedID 17677579
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A germanium inverse woodpile structure with a large photonic band gap
ADVANCED MATERIALS
2007; 19 (12): 1567-?
View details for DOI 10.1002/adma.200602906
View details for Web of Science ID 000247761800002
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Polarization controller for hollow-core fiber
OPTICS LETTERS
2007; 32 (11): 1524-1526
Abstract
We demonstrate a universal polarization controller for hollow-core fibers, a simple device consisting of three twisted fiber sections that makes use of the inherent birefringence of the air-core fiber. The device 5% bandwidth at 1550 nm is calculated from measured data to be approximately 13 nm.
View details for Web of Science ID 000247756600060
View details for PubMedID 17546176
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Manipulating light with photonic crystals
7th International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media (ETOPIM-7)
ELSEVIER SCIENCE BV. 2007: 221–28
View details for DOI 10.1016/j.physb.2006.12.078
View details for Web of Science ID 000246642900021
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Enhancing or suppressing self-focusing in nonlinear photonic crystals
APPLIED PHYSICS LETTERS
2007; 90 (16)
View details for DOI 10.1063/1.2724905
View details for Web of Science ID 000245870400024
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Strongly correlated two-photon transport in a one-dimensional waveguide coupled to a two-level system
PHYSICAL REVIEW LETTERS
2007; 98 (15)
Abstract
We show that two-photon transport is strongly correlated in one-dimensional waveguide coupled to a two-level system. The exact S matrix is constructed using a generalized Bethe-ansatz technique. We show that the scattering eigenstates of this system include a two-photon bound state that passes through the two-level system as a composite single particle. Also, the two-level system can induce effective attractive or repulsive interactions in space for photons. This general procedure can be applied to the Anderson model as well.
View details for DOI 10.1103/PhysRevLett.98.153003
View details for Web of Science ID 000245691400023
View details for PubMedID 17501344
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One-way total reflection with one-dimensional magneto-optical photonic crystals
APPLIED PHYSICS LETTERS
2007; 90 (12)
View details for DOI 10.1063/1.2716359
View details for Web of Science ID 000245135800033
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Theoretical investigation of compact couplers between dielectric slab waveguides and two-dimensional metal-dielectric-metal plasmonic waveguides
OPTICS EXPRESS
2007; 15 (3): 1211-1221
Abstract
We theoretically investigate the properties of compact couplers between high-index contrast dielectric slab waveguides and two-dimensional metal-dielectric-metal subwavelength plasmonic waveguides. We show that a coupler created by simply placing a dielectric waveguide terminated flat at the exit end of a plasmonic waveguide can be designed to have a transmission efficiency of ~70% at the optical communication wavelength. We also show that the transmission efficiency of the couplers can be further increased by using optimized multisection tapers. In both cases the transmission response is broadband. In addition, we investigate the properties of a Fabry-Perot structure in which light is coupled in and out of a plasmonic waveguide sandwiched between dielectric waveguides. Finally, we discuss potential fabrication processes for structures that demonstrate the predicted effects.
View details for Web of Science ID 000244682200051
View details for PubMedID 19532350
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Near-complete transmission through subwavelength hole arrays in phonon-polaritonic thin films
PHYSICAL REVIEW B
2007; 75 (7)
View details for DOI 10.1103/PhysRevB.75.075422
View details for Web of Science ID 000244533400108
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Overexpression of NDRG1 is an indicator of poor prognosis in hepatocellular carcinoma
MODERN PATHOLOGY
2007; 20 (1): 76-83
Abstract
Hepatocellular carcinoma is a highly lethal cancer that typically has poor prognosis. Prognostic markers can help in its clinical management and in understanding the biology of poor prognosis. Through an earlier gene expression study, we identified N-Myc downregulated gene 1 (NDRG1) to be significantly highly expressed in hepatocellular carcinoma compared to nontumor liver. As NDRG1 is a differentiation-related gene with putative metastasis suppressor activity, we investigated the clinical significance of its overexpression. Quantitative real-time polymerase chain reaction using an independent set of patient samples confirmed the significant overexpression of NDRG1 in hepatocellular carcinoma compared to nontumor liver samples (P<0.001). Additionally, high levels of NDRG1 transcript correlated with shorter overall survival (P<0.001), late tumor stage (P=0.001), vascular invasion (P=0.003), large tumor size (P=0.011), and high Edmondson-Steiner histological grade (P=0.005). Using immunohistochemistry, NDRG1 protein was found to be significantly overexpressed in hepatocellular carcinoma samples compared to nontumor liver or cirrhotic and benign liver lesions (P<0.001). Among the hepatocellular carcinoma samples, those which are moderately and poorly differentiated express higher levels of NDRG1 protein than those which are well-differentiated (P<0.005). Additionally, hepatocellular carcinomas with vascular invasion also express elevated levels of NDRG1 protein compared to those without vascular invasion (significant at P<0.005). Our results suggest NDRG1 to be a likely tumor marker for hepatocellular carcinoma, the overexpression of which is correlated with tumor differentiation, vascular invasion, and overall survival. Its significantly elevated expression in hepatocellular carcinoma could be a useful indicator of tumor aggressiveness and therefore patient prognosis.
View details for DOI 10.1038/modpathol.3800711
View details for Web of Science ID 000243005000010
View details for PubMedID 17170744
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OVERVIEW OF SIMULATION TECHNIQUES FOR PLASMONIC DEVICES
SURFACE PLASMON NANOPHOTONICS
2007; 131: 169-182
View details for DOI 10.1007/978-1-4020-4333-8_12
View details for Web of Science ID 000288851900013
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Three-dimensional electromagnetic metamaterials that homogenize to uniform non-Maxwellian media
Physical Review B
2007; 76 (11)
View details for DOI 113101 10.1103/PhysRevB.76.113101
-
The nonlinear effect from the interplay between the nonlinearity and the supercollimation of photonic crystal
Applied Physics Letters
2007; 91 (3)
View details for DOI 031105 10.1063/1.2739413
-
Enhancing or suppressing self-focusing in nonlinear photonic crystals
Applied Physics Letters
2007; 90 (16)
View details for DOI 161124 10.1063/1.2724905
-
Stopping single photons in one-dimensional circuit quantum electrodynamics systems
Physical Review B
2007; 75 (3)
View details for DOI 035320 10.1103/PhysRevB.75.035320
-
Strongly correlated multiparticle transport in one dimension through a quantum impurity
Physical Review A
2007; 76 (6)
View details for DOI 062709 10.1103/PhysRevA.76.062709
-
One-way total reflection with one-dimensional magneto-optical photonic crystals
Applied Physics Letters
2007; 90 (12)
View details for DOI 121133 10.1063/1.2716359
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Slow light - Dynamic photon storage
Nature Physics
2007; 3 (6): 372-374
View details for DOI 10.1038/nphys630
-
Spatial coherence of the thermal electromagnetic field in the vicinity of a dielectric slab
Physical Review E
2007; 76 (1)
View details for DOI 016601 10.1103/PhysRevE.76.016601
-
Modeling nonlinear optical phenomena in nanophotonics
Journal of Lightwave Technology
2007; 25 (9): 2539-2546
View details for DOI 10.1109/jlt.2007.903547
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Enlarging the bandwidth of nanoscale propagating plasmonic modes in deep-subwavelength cylindrical holes
Applied Physics Letters
2007; 91 (18)
View details for DOI 181118 10.1063/1.2803849
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A germanium inverse woodpile structure with a large photonic band gap
Advanced Materials
2007; 19 (12): 1567-+
View details for DOI 10.1002/adma.200602906
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Strongly correlated two-photon transport in a one-dimensional waveguide coupled to a two-level system
Physical Review Letters
2007; 98 (15)
View details for DOI 153003 10.1103/PhysRevLett.98.153003
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Compact couplers between dielectric and plasmonic slot waveguides
Conference on Integrated Optics - Devices, Materials, and Technology XI
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.701562
View details for Web of Science ID 000246061700024
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Near-complete transmission through subwavelength hole arrays in phonon-polaritonic thin films
Physical Review B
2007; 75 (7)
View details for DOI 075422 10.1103/PhysRevB.75.075422
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One-way electromagnetic waveguide
20th Annual Meeting of the IEEE-Lasers-and-Electro-Optics-Society
IEEE. 2007: 278–279
View details for Web of Science ID 000259345200136
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Stopping single photons in one-dimensional circuit quantum electrodynamics systems
PHYSICAL REVIEW B
2007; 75 (3)
View details for DOI 10.1103/PhysRevB.75.035320
View details for Web of Science ID 000243895400102
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Transmission enhancement and suppression by subwavelength hole arrays in polaritonic films
Conference on Photonic Crystal Materials and Devices VI
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.702917
View details for Web of Science ID 000246368900003
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One-way waveguide and strong photon-photon interaction in nanophotonic structures
IEEE/LEOS International Conference on Optical MEMS and Nanophotonics
IEEE. 2007: 181–182
View details for Web of Science ID 000251224200088
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Coherent few-photon quantum transport in one-dimensional systems
Conference on Advanced Optical and Quantum Memories and Computing IV
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.716467
View details for Web of Science ID 000246396000016
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Radiation loss of coupled-resonator waveguides in photonic-crystal slabs
Conference on Photonic Crystal Materials and Devices VI
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.704597
View details for Web of Science ID 000246368900014
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New properties of light in metamaterials
Conference on Metamaterials II
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.724178
View details for Web of Science ID 000250370100006
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Dynamically-tuned microresonator complexes
Conference on Laser Resonators and Beam Control IX
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.714597
View details for Web of Science ID 000245978400002
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Phonon polariton reflectance spectra in a silicon carbide membrane hole array
20th Annual Meeting of the IEEE-Lasers-and-Electro-Optics-Society
IEEE. 2007: 466–467
View details for Web of Science ID 000259345200232
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Compact couplers between dielectric and metal-dielectric-metal plasmonic waveguides
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference
IEEE. 2007: 895–896
View details for Web of Science ID 000268751000450
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Optical Characterization and Sensitivity Evaluation of Guided-Resonances in Photonic Crystal Slabs for Biosensing Applications
Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference
IEEE. 2007: 993–994
View details for Web of Science ID 000268751000499
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Sensitivity analysis of a photonic crystal structure for index-of-refraction sensing
Conference on Nanoscale Imaging, Spectroscopy, Sensing, and Actuation for Biomedical Applications IV
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.705670
View details for Web of Science ID 000245976200016
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Design of mid-infrared photodetectors enhanced by surface plasmons on grating structures
Conference on Integrated Optics - Devices, Materials, and Technology XI
SPIE-INT SOC OPTICAL ENGINEERING. 2007
View details for DOI 10.1117/12.698016
View details for Web of Science ID 000246061700022
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Extraordinary transmission through a poly-SiC membrane with subwavelength hole arrays
IEEE/LEOS International Conference on Optical MEMS and Nanophotonics
IEEE. 2007: 157–158
View details for Web of Science ID 000251224200077
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Enhanced second-harmonic generation in AlGaAs/AlxOy tightly confining waveguides and resonant cavities
OPTICS LETTERS
2006; 31 (24): 3626-3628
Abstract
We demonstrate second-harmonic generation (SHG) from sub-micrometer-sized AlGaAs/AlxOy artificially birefringent waveguides. The normalized conversion efficiency is the highest ever reported. We further enhanced the SHG using a waveguide-embedded cavity formed by dichroic mirrors. Resonant enhancements as high as approximately 10x were observed. Such devices could be potentially used as highly efficient, ultracompact frequency converters in integrated photonic circuits.
View details for Web of Science ID 000242560400022
View details for PubMedID 17130925
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Advances in theory of photonic crystals
JOURNAL OF LIGHTWAVE TECHNOLOGY
2006; 24 (12): 4493-4501
View details for DOI 10.1109/JLT.2006.886061
View details for Web of Science ID 000243888600005
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Dichroic mirror embedded in a submicrometer waveguide for enhanced resonant nonlinear optical devices
OPTICS LETTERS
2006; 31 (22): 3285-3287
Abstract
We report the design, fabrication and characterization of novel dichroic mirrors embedded in a tightly confining AlGaAs/Al(x)O(y) waveguide. Reflection at the first-harmonic wavelength as high as 93% is achieved, while high transmission is maintained at the second-harmonic wavelength. The measured cavity spectrum is in excellent agreement with finite-difference time-domain simulations. Such a mirror is essential for achieving resonant enhancement of second-harmonic generation.
View details for Web of Science ID 000241799700022
View details for PubMedID 17072398
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Radiation loss of coupled-resonator waveguides in photonic-crystal slabs
APPLIED PHYSICS LETTERS
2006; 89 (19)
View details for DOI 10.1063/1.2387131
View details for Web of Science ID 000241960400014
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Cut-through metal slit array as an anisotropic metamaterial film
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
2006; 12 (6): 1116-1122
View details for DOI 10.1109/JSTQE.2006.879577
View details for Web of Science ID 000243013600007
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Conditions for designing single-mode air-core waveguides in three-dimensional photonic crystals
APPLIED PHYSICS LETTERS
2006; 89 (16)
View details for DOI 10.1063/1.2362983
View details for Web of Science ID 000241405200003
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Design of midinfrared photodetectors enhanced by surface plasmons on grating structures
APPLIED PHYSICS LETTERS
2006; 89 (15)
View details for DOI 10.1063/1.2360896
View details for Web of Science ID 000241247900016
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All-angle negative refraction and evanescent wave amplification using one-dimensional metallodielectric photonic crystals
APPLIED PHYSICS LETTERS
2006; 89 (15)
View details for DOI 10.1063/1.2360187
View details for Web of Science ID 000241247900002
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Suppressing the effect of disorders using time-reversal symmetry breaking in magneto-optical photonic crystals: An illustration with a four-port circulator
PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS
2006; 4 (3): 132-140
View details for DOI 10.1016/j.photonics.2006.02.001
View details for Web of Science ID 000240118800002
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Dynamically tuned coupled-resonator delay lines can be nearly dispersion free
OPTICS LETTERS
2006; 31 (13): 1985-1987
Abstract
We investigate dispersion effects in dynamically tuned, coupled-resonator delay lines. Provided that the system is tuned to a zero-bandwidth state, a signal can be delayed indefinitely with almost no dispersion. We present a theoretical analysis of such a light-stopping system and verify the results using numerical simulations.
View details for Web of Science ID 000238494600015
View details for PubMedID 16770407
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Experimental realization of an on-chip all-optical analogue to electromagnetically induced transparency
PHYSICAL REVIEW LETTERS
2006; 96 (12)
Abstract
We provide the first experimental observation of structure tuning of the electromagnetically induced transparency-like spectrum in integrated on-chip optical resonator systems. The system consists of coupled silicon ring resonators with 10 microm diameter on silicon, where the coherent interference between the two coupled resonators is tuned. We measured a transparency-resonance mode with a quality factor of 11,800.
View details for DOI 10.1103/PhysRevLett.96.123901
View details for Web of Science ID 000236467000020
View details for PubMedID 16605904
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Anomalous modal structure in a waveguide with a photonic crystal core
OPTICS LETTERS
2006; 31 (6): 742-744
Abstract
We analyze a dielectric waveguide with a photonic crystal core. Using constant frequency contour analysis, we show that the modal behavior of this structure is drastically different from that of a conventional slab waveguide. In particular, at a given frequency the lowest-order guided mode can have an odd symmetry or can have more than one nodal plane in its field distribution. Also, there exist several single-mode regions with a different modal profile in each region. Finally, a single-mode waveguide for the fundamental mode with a large core and strong confinement can be realized. All these behaviors are confirmed by our three-dimensional finite-difference time-domain simulations.
View details for Web of Science ID 000235833400022
View details for PubMedID 16544609
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Systematic photonic crystal device design: Global and local optimization and sensitivity analysis
IEEE JOURNAL OF QUANTUM ELECTRONICS
2006; 42 (3-4): 266-279
View details for DOI 10.1109/JQE.2005.862038
View details for Web of Science ID 000236674000006
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Model dispersive media in finite-difference time-domain method with complex-conjugate pole-residue pairs
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
2006; 16 (3): 119-121
View details for DOI 10.1109/LMWC.2006.869862
View details for Web of Science ID 000236124400007
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All-angle negative refraction for surface plasmon waves using a metal-dielectric-metal structure
PHYSICAL REVIEW LETTERS
2006; 96 (7)
Abstract
We show that a metal-dielectric-metal structure can function as a negative refraction lens for surface plasmon waves on a metal surface. The structure is uniform with respect to a plane of incidence and operates at the optical frequency range. Using three-dimensional finite-difference time-domain simulations, we demonstrate the imaging operation of the structure with realistic material parameters including dispersions and losses. Our design should facilitate the demonstration of many novel effects associated with negative refraction on chip at optical wavelength ranges. In addition, this structure provides a new way of controlling the propagation of surface plasmons, which are important for nanoscale manipulation of optical waves.
View details for DOI 10.1103/PhysRevLett.96.073907
View details for Web of Science ID 000235554100034
View details for PubMedID 16606095
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Direct-write assembly of three-dimensional photonic crystals: Conversion of polymer scaffolds to silicon hollow-woodpile structures
ADVANCED MATERIALS
2006; 18 (4): 461-?
View details for DOI 10.1002/adma.200501447
View details for Web of Science ID 000235689200013
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Waveguides in inverted opal photonic crystals
OPTICS EXPRESS
2006; 14 (2): 866-878
Abstract
Waveguiding phenomena are investigated in an inverted opal photonic crystal made of interpenetrating air spheres, coated with amorphous Ge. Here we focus on the complete gap between the 8th and the 9th band, since a projected band analysis reveals that it is difficult to use the large lower incomplete gap for guiding purposes. Two kinds of line defects are analyzed within this photonic structure, with the plane-wave expansion method. The first one consists of an air cylinder in the Gamma-K direction. It gives rise to a large number of defect modes in the bandgap. Most of these modes have large field components at the surface. The second defect is an array of air spheres, also along the Gamma-K direction. This is shown to avoid the surface-like modes and sustain only two modes associated with different polarizations, in the frequency range of interest. The air mode waveguiding bandwidth reaches up to 113 nm centered at a wavelength of 1.5 microm.
View details for Web of Science ID 000235012000047
View details for PubMedID 19503406
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Guided modes supported by plasmonic films with a periodic arrangement of subwavelength slits
APPLIED PHYSICS LETTERS
2006; 88 (3)
View details for DOI 10.1063/1.2164905
View details for Web of Science ID 000234757100001
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Integrated biomedical nanosensor using guided resonance in photonic crystal structures
Conference on Nanobiophotonics and Biomedical Applications III
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for DOI 10.1117/12.647312
View details for Web of Science ID 000237699500014
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Frequency domain modeling of nanophotonic devices
PHOTONICS: DESIGN, TECHNOLOGY, AND PACKAGING II
2006; 6038
View details for DOI 10.1117/12.651341
View details for Web of Science ID 000236542100021
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Plasmonic films with a periodic arrangement of sub-wavelength slits
Conference on Photonic Crystal Materials and Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for DOI 10.1117/12.648510
View details for Web of Science ID 000238247900032
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Tunable terahertz Bloch oscillations in graded-index photonic crystals
Conference on Photonic Crystal Materials and Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for DOI 10.1117/12.646604
View details for Web of Science ID 000238247900031
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Subwavelength plasmonic waveguide structures based on slots in thin metal films
INTEGRATED OPTICS: DEVICES, MATERIALS, AND TECHNOLOGIES X
2006; 6123
View details for DOI 10.1117/12.646789
View details for Web of Science ID 000237286300006
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Direct-write assembly of three-dimensional photonic crystals: Conversion of polymer scaffolds to silicon hollow-woodpile structures
Advanced Materials
2006; 18 (4): 461-+
View details for DOI 10.1002/adma.200501447
-
Radiation loss of coupled-resonator waveguides in photonic-crystal slabs
Applied Physics Letters
2006; 89 (19)
View details for DOI 191114 10.1063/1.2387131
-
All-angle negative refraction for surface plasmon waves using a metal-dielectric-metal structure
Physical Review Letters
2006; 96 (7)
View details for DOI 073907 10.1103/PhysRevLett.96.073907
-
Design of midinfrared photodetectors enhanced by surface plasmons on grating structures
Applied Physics Letters
2006; 89 (15)
View details for DOI 151116 10.1063/1.2360896
-
Cut-through metal slit array as an anisotropic metamaterial film
Ieee Journal of Selected Topics in Quantum Electronics
2006; 12 (6)
View details for DOI 10.1109/jstqe.2006.879577
-
Conditions for designing single-mode air-core waveguides in three-dimensional photonic crystals
Applied Physics Letters
2006; 89 (16)
View details for DOI 161103 10.1063/1.2362983
-
Waveguides in inverted opal photonic crystals
Optics Express
2006; 14 (2): 866-878
View details for DOI 10.1364/opex.14.000866
-
Guided modes supported by plasmonic films with a periodic arrangement of subwavelength slits
Applied Physics Letters
2006; 88 (3)
View details for DOI 031101 10.1063/1.2164905
-
Air-bridged photonic crystal slabs at visible and near-infrared wavelengths
Physical Review B
2006; 73 (11)
View details for DOI 115126 10.1103/PhysRevB.73.115126
-
Experimental realization of an on-chip all-optical analogue to electromagnetically induced transparency
Physical Review Letters
2006; 96 (12)
View details for DOI 123901 10.1103/PhysRevLett.96.123901
-
All-angle negative refraction and evanescent wave amplification using one-dimensional metallodielectric photonic crystals
Applied Physics Letters
2006; 89 (15)
View details for DOI 151102 10.1063/1.2360187
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A polarization controller for air-core photonic-bandgap fiber
Conference on Optical Fiber Communications/National Fiber Optic Engineers Conference
OPTICAL SOC AMERICA. 2006: 681–683
View details for Web of Science ID 000259602600200
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Dynamically-tuned coupled-resonator delay lines can be nearly dispersion free
Conference on Advanced Optical and Quantum Memories and Computing III
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for Web of Science ID 000237288300001
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Photonic crystals for communications: Stopping light and miniaturized non-reciprocal devices
Conference on Optical Fiber Communications/National Fiber Optic Engineers Conference
OPTICAL SOC AMERICA. 2006: 2119–2121
View details for Web of Science ID 000259602601156
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Controlling diffraction and waveguide modes by exploiting spatial dispersions in photonic crystals
Conference on Photonic Crystal Materials and Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for DOI 10.1117/12.649564
View details for Web of Science ID 000238247900025
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Magneto-optical circulator in two-dimensional photonic crystals
Conference on Photonic Crystal Materials and Devices IV
SPIE-INT SOC OPTICAL ENGINEERING. 2006
View details for DOI 10.1117/12.646874
View details for Web of Science ID 000238247900009
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Guided subwavelength plasmonic mode supported by a slot in a thin metal film
OPTICS LETTERS
2005; 30 (24): 3359-3361
Abstract
We demonstrate the existence of a bound optical mode supported by a slot in a thin metallic film deposited on a substrate, with slot dimensions much smaller than the wavelength. The modal size is almost completely dominated by the near field of the slot. Consequently, the size is very small compared with the wavelength, even when the dispersion relation of the mode approaches the light line of the surrounding media. In addition, the group velocity of this mode is close to the speed of light in the substrate, and its propagation length is tens of micrometers at the optical communication wavelength.
View details for Web of Science ID 000233827000033
View details for PubMedID 16389831
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Understanding air-core photonic-bandgap fibers: Analogy to conventional fibers
JOURNAL OF LIGHTWAVE TECHNOLOGY
2005; 23 (12): 4169-4177
View details for DOI 10.1109/JLT.2005.859406
View details for Web of Science ID 000234417100022
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Coherent single photon transport in a one-dimensional waveguide coupled with superconducting quantum bits
PHYSICAL REVIEW LETTERS
2005; 95 (21)
Abstract
A recent theoretical analysis and experimental results show that interesting transport properties of a single microwave photon emerge when a quantum bit in a cavity is coupled to a one-dimensional waveguide. Here we adopt a real-space model Hamiltonian to give a unified approach which accounts for the experimental results, and make new predictions on the properties of single photon transport, such as the general Fano line shape, symmetric vacuum Rabi splitting for a leaky cavity at resonance, and a one-photon switching capability.
View details for DOI 10.1103/PhysRevLett.95.213001
View details for Web of Science ID 000233362100018
View details for PubMedID 16384136
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Propagating modes in subwavelength cylindrical holes
49th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication
A V S AMER INST PHYSICS. 2005: 2675–78
View details for DOI 10.1116/1.2130344
View details for Web of Science ID 000234613200077
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Bends and splitters in metal-dielectric-metal subwavelength plasmonic waveguides
APPLIED PHYSICS LETTERS
2005; 87 (13)
View details for DOI 10.1063/1.2056594
View details for Web of Science ID 000232060200002
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Conditions for self-collimation in three-dimensional photonic crystals
OPTICS LETTERS
2005; 30 (18): 2397-2399
Abstract
We introduce the theoretical criterion for achieving three-dimensional self-collimation of light in a photonic crystal. Based on this criterion, we numerically demonstrate a body-center-cubic structure that supports wide-angle self-collimation and is directly compatible with the recently developed holographic fabrication technique. We further show that both bends and beam splitters can be introduced into this structure by the use of interfaces.
View details for Web of Science ID 000231964600017
View details for PubMedID 16196331
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Wannier basis design and optimization of a photonic crystal waveguide crossing
IEEE PHOTONICS TECHNOLOGY LETTERS
2005; 17 (9): 1875-1877
View details for DOI 10.1109/LPT.2005.852326
View details for Web of Science ID 000231453500038
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Coherent photon transport from spontaneous emission in one-dimensional waveguides
OPTICS LETTERS
2005; 30 (15): 2001-2003
Abstract
A two-level system coupled to a one-dimensional continuum is investigated. By using a real-space model Hamiltonian, we show that spontaneous emission can coherently interfere with the continuum modes and gives interesting transport properties. The technique is applied to various related problems with different configurations, and analytical solutions are given.
View details for Web of Science ID 000230714400029
View details for PubMedID 16092246
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Tunable terahertz Bloch oscillations in chirped photonic crystals
PHYSICAL REVIEW B
2005; 72 (7)
View details for DOI 10.1103/PhysRevB.72.075119
View details for Web of Science ID 000231564500055
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Dynamic photonic structures: Stopping, storage, and time reversal of light
STUDIES IN APPLIED MATHEMATICS
2005; 115 (2): 233-253
View details for Web of Science ID 000230285400004
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Displacement sensing using evanescent tunneling between guided resonances in photonic crystal slabs
JOURNAL OF APPLIED PHYSICS
2005; 98 (3)
View details for DOI 10.1063/1.1999031
View details for Web of Science ID 000231246100002
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Optical circulators in two-dimensional magneto-optical photonic crystals
OPTICS LETTERS
2005; 30 (15): 1989-1991
Abstract
We propose an optical circulator formed of a magneto-optical cavity in a 2D photonic crystal