Surface acoustic waves to monitor active THz metagrating based on VO2

TL;DR

This paper introduces a theoretical method using surface acoustic waves on LiNbO3 to monitor the state changes of VO2 pixels in active THz metagratings, enabling in-situ, non-radiative feedback for device health and defect detection.

Contribution

It presents a novel approach to monitor VO2-based active THz metagratings in real-time using SAWs, without requiring incident radiation, advancing metasurface diagnostics.

Findings

SAW device can detect VO2 pixel state changes via RF response

Method enables in-situ monitoring of metasurface aging and defects

Modeling of tunable and gradient gratings demonstrates versatility

Abstract

We theoretically propose a new approach to in-situ monitor the altered states of pixels in VO2 based active THz amplitude metagrating by using surface acoustic waves (SAWs) generated in LiNbO3 substrate. A single broadband RF response of the SAW device consists of N narrowband frequency channels which code the feedback information on the current pixels states. This way the resistance alteration due to metal-to-insulator transition of all VO2 based pixels of the active THz grating is monitored in advance even without incident radiation. The method provides important new options of monitoring a metasurface aging as well as incorrect switching related to technological defects. Using of the SAW device in all-electrically addressed VO2 based binary grating with tunable period as well as advanced gradient type gratings are modeled.