Mid-infrared active metasurface based on Si/VO2 hybrid meta-atoms

Active metasurfaces whose optical properties can be tuned by an external stimulus have attracted great research interest recently. Introduction of VO2 phase change material in all-dielectric metasurfaces has been demonstrated to modulate the resonance wavelength and amplitude in the visible to near-infrared wavelength range. In this study, we report a mid-infrared active metasurface based on Si/VO2 hybrid meta-atoms. By incorporating VO2 thin films in different locations of Si/VO2 nanodisks, we demonstrate different modulation amplitude of the electric or magnetic resonance scattering cross sections, leading to drastically different transmission spectrum upon VO2 insulator to metal phase transition. The physical mechanism is originated from the field profiles of the resonance modes, which interact with VO2 differently depending on its locations. Based on this mechanism, we experimentally demonstrated a large modulation of the transmittance from 82% to 28% at the 4.6 mu m wavelength. Our work demonstrates a promising potential of VO2-based active all-dielectric metasurface for mid-infrared photonic applications such as infrared camouflage, chemical/biomedical sensing, optical neuro- morphic computing, and multispectral imaging. (C) 2022 Chinese Laser Press

Automated summary

This study reports a mid-infrared active metasurface based on Si/VO2 hybrid meta-atoms, which demonstrates different modulation amplitudes of the electric or magnetic resonance scattering cross sections by incorporating VO2 thin films in different locations. The research highlights the potential importance of this active metasurface for mid-infrared photonic applications.