Photosensitive chalcogenide metasurfaces supporting bound states in the continuum

TL;DR

This paper demonstrates tunable metasurfaces with sharp Fano resonances based on bound states in the continuum, using arsenic trisulfide glass whose optical properties can be post-fabrication tuned by light exposure.

Contribution

It introduces a method to dynamically tune bound states in the continuum metasurfaces using photosensitive chalcogenide glass, enabling post-fabrication control of optical resonances.

Findings

Resonant wavelength can be tuned by light exposure.

Experimental validation of tunable Fano resonances.

Potential for adaptive optical devices.

Abstract

We study, both theoretically and experimentally, tunable metasurfaces supporting sharp Fano-resonances inspired by optical bound states in the continuum. We explore the use of arsenic trisulfide (a photosensitive chalcogenide glass) having optical properties which can be finely tuned by light absorption at the post-fabrication stage. We select the resonant wavelength of the metasurface corresponding to the energy below the arsenic trisulfide bandgap, and experimentally control the resonance spectral position via exposure to the light of energies above the bandgap.