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arXiv · 2602.11535

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

Kai Qi·Guoxiang Wang·Xiang Shen·Yixiao Gao
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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.

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Kai Qi, Guoxiang Wang, Xiang Shen, Yixiao Gao. 2026-02-12. Switchable high-Q light absorbers based on phase-change resonant metasurfaces. https://doi.org/10.1088/2040-8986%2Fae2e0e

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