Structured vanadium dioxide metamaterial for tunable broadband terahertz absorption

A tunable broadband terahertz (THz) absorber based on vanadium dioxide (VO2) is proposed, which is composed of a structured VO2 metamaterial layer, a dielectric layer, and a metal layer. The simulation results show that the peak absorption intensity of the absorber can be dynamically adjusted from 3.6% to 100% by changing the conductivity of VO2. When the conductivity of VO2 is 2x10(5) S/m, an excellent broadband absorption phenomenon appears, and the bandwidth of absorption rate greater than 90% is as wide as 4.10 THz from 3.25 THz to 7.35 THz. The impedance matching theory and the electric field distribution are used to explain the physical mechanism of the proposed absorber. In addition, the absorber shows the advantages of polarization-insensitiveness and wide-angle absorption. It is expected that this absorber can have potential applications such as modulators and photoelectric switches. (C) 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

A tunable broadband terahertz absorber based on vanadium dioxide (VO2) has been proposed, showing excellent broadband absorption and advantages of polarization-insensitiveness and wide-angle absorption. Potential applications include modulators and photoelectric switches.