A terahertz multi/dual-band tunable metamaterial absorber based on vanadium dioxide

Abstract

Abstract. A multi/dual-band switchable dual-function metamaterial absorber is presented in this paper. The phase-change material vanadium dioxide (VO2) is incorporated into the absorber structure. By taking advantage of the reversible phase change characteristics of VO2, which can be tuned between the insulating state and the metallic state, the conversion between different functions is achieved. Simulation results show that within the frequency range of 2.5 to 6.5 THz, when VO2 is in the insulating state, the structure acts as a triple-band absorber, with corresponding resonant frequencies of 3.03, 3.83, and 5.51 THz, each achieving an absorptivity of 99%, thus realizing near-perfect absorption of electromagnetic waves. When VO2 switches to the metallic state, the structure transforms into a dual-band absorber, and both absorption peaks exhibit absorptivities exceeding 97%. Furthermore, the influence of geometric parameters on the absorption performance is analyzed in detail, and characteristics such as polarization insensitivity, a wide incident angle tolerance, and sensing capabilities are discussed. This work is of significant importance for the design of novel tunable metamaterial absorbers and their applications in sensing and communication.