Switchable Terahertz Absorber from Single Broadband to Dual Broadband Based on Graphene and Vanadium Dioxide

A multifunctional switchable terahertz (THz) absorber based on graphene and vanadium dioxide (VO2) is presented. The properties of the absorber are studied theoretically by the finite-difference time-domain (FDTD) method. The results illustrate that the structure switches between the single-broadband or double-broadband absorption depending on the temperature of VO2. Moreover, the amplitude of the absorptivity can be adjusted by changing the Fermi energy level (E-F) of graphene or the conductivity of VO2 separately. Via impedance matching theory, the physical mechanism of the absorber is researched. Furthermore, the effects of incidence angle on absorption have also been studied. It is found that the absorber is insensitive to the polarization of electromagnetic waves.

Automated summary

This paper presents a multifunctional switchable terahertz (THz) absorber based on graphene and vanadium dioxide (VO2), which can switch between single or double broadband absorption by adjusting the temperature of VO2. The absorptivity's amplitude can be adjusted by changing the Fermi energy level of graphene or the conductivity of VO2 separately. The physical mechanism of the absorber and the effects of incidence angle on absorption have been studied, indicating that the absorber is insensitive to the polarization of electromagnetic waves.