Switchable terahertz absorber from single broadband to triple-narrowband

Abstract

We proposed a switchable multifunctional terahertz (THz) absorber based on graphene and vanadium dioxide (VO 2 ), and investigated the absorption properties and the tuning of the absorber by using Computer Simulation Technology (CST) microwave studio. It was found that, when VO 2 is in dielectric phase, the structure shows a single broadband absorption from 0.8 to 2.4 THz range. The amplitude of the absorption can be tuned from 95 % to 20 % by changing the Fermi energy level of the graphene. And the absorption is found to be insensitive to the polarization angle and the incident angle. When VO 2 is in metallic phase, the absorber shows triple narrowband absorption. Utilizing impedance matching theory and transmission line theory, the physical mechanism of the absorber is investigated. • The designed structure is simple and easy to make in practice. • The proposed absorber has high efficient absorptivity. • The absorber enables functional switching between broadband and triple narrowband. • The absorber can achieve dynamic tuning of the single broadband absorptance.