Switchable bifunctional metasurfaces: nearly perfect retroreflection and absorption at THz regime

TL;DR

This paper presents a VO2-based metasurface that can switch between retroreflection and absorption at THz frequencies by exploiting VO2's phase transition, enabling versatile wave manipulation.

Contribution

It introduces a novel switchable bifunctional metasurface leveraging VO2's phase change for combined retroreflection and absorption functionalities.

Findings

Achieves switchable functionality via temperature control.

Demonstrates nearly perfect retroreflection and absorption.

Potential applications in detection and anti-detection devices.

Abstract

Here we make use of vanadium dioxide (VO2) to design a bifunctional metasurface working at the same targeted frequency. With the increase of temperature, the functionality of the designed metasurface can switch from a multi-channel retroreflector to a perfect absorber, caused by the phase transition of VO2 from insulator to conductor. Different from traditional bifunctional metasurfaces designed by simple composition of two functionalities, our proposed bifunctional metasurface is based on the interaction between two functionalities. The device shows good potential for the combination of wavefront manipulation and optical absorption, therefore providing a promising approach for switchable detection and anti-detection devices.