Tunable multiple broadband terahertz perfect absorber based on vanadium dioxide

Abstract A multiple broadband terahertz (THz) perfect absorber which can be dynamically adjustable is designed, consisted of the vanadium dioxide (VO2) layer, a metal ground plane, and a sandwiched silicon dioxide (SiO2) layer. The results of simulation indicate the bandwidths more than 90% absorption are 0.44 THz, 0.26 THz, 0.55 THz, 0.43 THz, 0.39 THz, respectively, ranging from 0 to 9.5 THz. The absorption varies with VO2 conductivity and can be dynamically adjusted from 7% to 99.9%. To obtain physical mechanism of the absorber, impedance matching theory, as well as Fabry–Perot resonance theory are introduced, and the physical source of the perfect absorption peaks are analyzed by electric field distribution. Besides, it also has the features of wide-angle absorption and polarization insensitivity. Therefore, it can be used in THz sensors, detectors, and stealth technology.