Switchable high-Q light absorbers based on phase-change resonant metasurfaces

TL;DR

This paper introduces a reconfigurable metasurface that can switch between perfect absorption and reflection states by utilizing phase-change materials, enabling dynamic control of light with high Q-factor resonances.

Contribution

It presents a novel switchable high-Q light absorber using phase-change resonant metasurfaces, actively tunable via phase transitions of embedded low-loss PCM.

Findings

Achieves switchable perfect absorption and reflection states.

Demonstrates active tuning of resonance Q factor.

Potential applications in photodetection and thermal emission control.

Abstract

In this paper, we propose a switchable high-Q light absorber based on a reconfigurable metasurface enabled by a lowloss phase-change material (PCM). By leveraging the coupling between guided-mode resonance and Fabry-Perot modes, mediated by the phase-transition dynamics of the embedded PCM, the resonance Q factor can be actively tuned. This allows the system to switch from a perfect dark state, governed by the physics of bound states in the continuum, to a critically coupled resonance with a finite Q factor. Consequently, the metasurface exhibits perfect absorption in the amorphous state and a reflection-dominated response in the crystalline state. The proposed metasurface holds significant potential for diverse nanophotonic applications, including photodetection and thermal emission control.