Tunable Terahertz Bi-Functional Metasurfaces Based on Hybrid-Patterned Vanadium Dioxide and Conventional

In this study, we examine a seven-layer bi-functional broadband terahertz array device that is actively tunable. The device comprises symmetrical polypropylene layers, a silicon dioxide layer, and hybrid-patterned metasurfaces, with a vanadium dioxide (VO
2
) layer at the center. The VO
2
layer allows the device to switch between dual-directional absorption and efficient transmission in the THz range due to its insulator-to-metal transition. According to simulation results, the suggested device functions as a tunable dual-directional absorber with a maximum absorption efficiency of 99% when VO
2
is in its metallic state. Three effective transmission peaks close to 100% from 1 THz to 2.3 THz are achievable when VO
2
functions as a dielectric. The analysis of free charge distribution clarifies the physical mechanisms behind dual-directional absorption and the three transmission peaks. Additionally, the device exhibits wide-angle absorption and transmission as well as polarization insensitivity. The proposed structure provides a novel approach for the creation of adjustable, multifunctional THz metasurface devices with potential applications in fields such as sensing, cloaking, and filtering.