Dynamic beam scanning metasurface with high reflectivity and independent phase control based on phase change materials

Abstract

Laser phased array radar has a broad application prospect in extreme weather imaging, real-time meteorological monitoring, intelligent self-driving, and adaptive scanning. Dynamic metamaterials solve the problems of miniaturization and poor robustness of traditional devices and provide the possibility of a tunable phased array. In these metasurfaces, the wavefront control of the incident beam is mainly realized by timing control, with extremely low reflectivity (≤5%) and a small scanning angle. We present an all-solid-state electrically tunable metasurface array based on phase change materials (PCM). Through the simple structure of a tunable vanadium dioxide (VO2) - gold resonator, the top gate is controlled to realize a near-infrared band beam scanning. Close in construction, simple in operation, and portable. It demonstrates the reflection phase and reflectance have high tunability when the operating wavelength is 1.55 um. Driven by the top grid, a phase monotone modulation range of more than 200° is generated, with a minimum reflectivity of more than 15 % and a maximum reflected beam field of view of ±25.6°. In principle, the electrically driven phase control enables a single resonant element to have independent electrical addressing capability, which paves the way for the application of metasurface optical elements in imaging and sensing technologies.