Document Type
Article
Publication Date
9-2-2020
Abstract
Actively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be considered “local” in that their operation depends on the responses of individual meta-units. In contrast, “nonlocal” metasurfaces function based on the modes supported by many adjacent meta-units, resulting in sharp spectral features but typically no spatial control of the outgoing wavefront. Recently, nonlocal metasurfaces based on quasi-bound states in the continuum have been shown to produce designer wavefronts only across the narrow bandwidth of the supported Fano resonance. Here, we leverage the enhanced light-matter interactions associated with sharp Fano resonances to explore the active modulation of optical spectra and wavefronts by refractive- index tuning and mechanical stretching. We experimentally demonstrate proof-of-principle thermo-optically tuned nonlocal metasurfaces made of silicon and numerically demonstrate nonlocal metasurfaces that thermo- optically switch between distinct wavefront shapes. This meta-optics platform for thermally reconfigurable wave- front shaping requires neither unusual materials and fabrication nor active control of individual meta-units.
Comments
This article was originally published in Nanophotonics, available at https://doi.org/10.1515/nanoph-2020-0375
This work is distributed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).