Dual-band Absorption using a Phase Transition Metal

This article elucidates the switchable absorption properties by employment of a thin film of vanadium dioxide. Gold patterns are designed over a quartz substrate which exhibit plasmonic resonance. In the insulator state of vanadium dioxide, the absorption of electromagnetic waves is lower as compared to its metallic state. The insulator-metal phase transition alters the electrical, thermal and optical properties of vanadium dioxide. The proposed absorber exhibits more than 98% absorption at 2.95 THz and 4.6 THz in the metallic state. Below the transition temperature, vanadium dioxide behaves as an insulator which allows transmission of electromagnetic waves. By varying the temperature, the rate of absorption can be changed due to variation of refractive index and permittivity of vanadium dioxide. Numerical simulations have been conducted using CST 2021 software.