Doctor of Philosophy, Hong Kong University Of Science & Technology (2014)
Shanhui Fan, Postdoctoral Faculty Sponsor
- 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
Polarization control with dielectric helix metasurfaces and arrays
2018; 26 (17): 21664–74
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
- Pulse shortening in an actively mode-locked laser with parity-time symmetry APL PHOTONICS 2018; 3 (8)
- Photonic crystal slab Laplace operator for image differentiation OPTICA 2018; 5 (3): 251–56
- Synthetic space with arbitrary dimensions in a few rings undergoing dynamic modulation PHYSICAL REVIEW B 2018; 97 (10)
- Effects of non-Hermitian perturbations on Weyl Hamiltonians with arbitrary topological charges PHYSICAL REVIEW B 2018; 97 (7)
Photonic Weyl Point in a 2D Resonator Array with a Synthetic Frequency Dimension
View details for Web of Science ID 000427296200309
Experiment Realization of Synthetic Weyl Points In Optical Regime
View details for Web of Science ID 000427296200305
Photonic Weyl point in a two-dimensional resonator lattice with a synthetic frequency dimension
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
- Time reversal of a wave packet with temporal modulation of gauge potential PHYSICAL REVIEW B 2016; 94 (14)
- The existence of topological edge states in honeycomb plasmonic lattices NEW JOURNAL OF PHYSICS 2016; 18
Hyperbolic Weyl Point in Reciprocal Chiral Metamaterials.
Physical review letters
2016; 117 (5): 057401-?
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