Polarization-insensitive and ultra-bandwidth terahertz metamaterial absorber based on vanadium dioxide

In this paper, we propose a polarization-insensitive and ultra-bandwidth terahertz metamaterial absorber based on vanadium dioxide. The absorber consists of a vanadium dioxide (VO₂) resonant layer, a photonic crystal slab dielectric layer, and a metallic reflection layer. When VO₂ is in the metallic state, the absorber realizes ultra-bandwidth absorption in the frequency range of 4.78-13.28 THz, with a high average absorption rate of 97.5%, an absorption bandwidth of 8.5 THz, and a relative bandwidth of 94.1%. The absorption of the absorber can be dynamically adjusted between 1.2% and 97.5% by varying the conductivity of vanadium dioxide. The absorber has polarization insensitivity and wide-angle absorption characteristics, and the absorption rate is maintained above 80% in the incident angle range of 0°-50°. In addition, ultra-wideband absorbers are suitable for multi-band compatible systems (such as the collaborative design of 6G communication and infrared stealth).