Controlling wideband absorption and electromagnetically induced transparency via a phase change material

Institute of Electromagnetics and Acoustics, Xiamen University - Xiamen 361005, China

^(a) zhysong@xmu.edu.cn

Received: 21 February 2020
Accepted: 17 March 2020

Abstract

A terahertz switchable metamaterial is presented with bifunctional properties of absorption and electromagnetically induced transparency based on phase transition of vanadium dioxide. When vanadium dioxide is metal, the designed configuration acts as a wideband absorber consisting of a vanadium dioxide square-shaped array, a dielectric spacer, and a vanadium dioxide continuous film. The working frequency of absorptance larger than 90% ranges from 0.271 THz to 0.592 THz with bandwidth ratio 74.4%. The absorber can work well over a wide range of incident angle for transverse electric polarization and transverse magnetic polarization. When vanadium dioxide is insulator, the designed configuration acts as an analog of electromagnetically induced transparency in the terahertz frequency. The interaction between metallic cross and split ring resonator gives rise to a transparency peak in the transmission spectrum. The performance of electromagnetically induced transparency is robust against polarization and incident angle. This design could provide some prospects in designing switchable terahertz devices, such as the modulator, filter, and optoelectronic components.