Tony Heinz, Postdoctoral Faculty Sponsor
All-dielectric scale invariant waveguide.
2023; 14 (1): 6675
Total internal reflection (TIR) governs the guiding mechanisms of almost all dielectric waveguides and therefore constrains most of the light in the material with the highest refractive index. The few options available to access the properties of lower-index materials include designs that are either lossy, periodic, exhibit limited optical bandwidth or are restricted to subwavelength modal volumes. Here, we propose and demonstrate a guiding mechanism that leverages symmetry in multilayer dielectric waveguides as well as evanescent fields to strongly confine light in low-index materials. The proposed waveguide structures exhibit unusual light properties, such as uniform field distribution with a non-Gaussian spatial profile and scale invariance of the optical mode. This guiding mechanism is general and can be further extended to various optical structures, employed for different polarizations, and in different spectral regions. Therefore, our results can have huge implications for integrated photonics and related technologies.
View details for DOI 10.1038/s41467-023-42234-1
View details for PubMedID 37865707
- Low-loss composite photonic platform based on 2D semiconductor monolayers NATURE PHOTONICS 2020; 14 (4): 256-+
Integrated near-field thermo-photovoltaics for heat recycling.
2020; 11 (1): 2545
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
- Integrated photonics for NASA applications SPIE-INT SOC OPTICAL ENGINEERING. 2019