A dynamically tunable polarization-insensitive broadband vanadium dioxide-assisted absorber for terahertz applications

Abstract

Abstract Research into tunable broadband absorbers has recently grown in popularity due to the terahertz technology’s spectacular development. This article proposes and analyzes a metamaterial structure based on vanadium dioxide (VO 2 ) that can be used as a broadband terahertz absorber, which is tuned dynamically. The upper layer of the absorber is made of VO 2 , the ground is composed of gold, and middle dielectric substrate is made of polyimide. The prescribed design provides more than 95 % of absorption with 4 THz bandwidth from 3.3 to 7.3 THz. Moreover, absorption peak intensity can be constantly enhanced from 5 % to 97 % when the VO 2 ’s conductivity varies from 200 to 2 × 10 5 S/m. This transition enables dynamic control between high absorption and high reflection states. This research endeavours to thoroughly investigate VO 2 -based THz Metamaterial Absorber (MMA), encompassing all aspects of the design validation and modelling using an electronic equivalent lumped design. The conductive phenomena of VO 2 radiating patch to achieve a high percentage absorption for the relevant absorption frequency band is very useful to understand. Additionally, it has been verified that the polarization angle has no effect on the absorptance. The prescribed absorber has potential applications including terahertz imaging, sensing, detection, electromagnetic cloaking, and optoelectronic switches.