Research on dual-controlled terahertz metamaterial broadband absorber based on vanadium dioxide and graphene

A dual-controlled broadband terahertz absorber based on graphene and vanadium dioxide is proposed. Numerical results reveal that excellent absorption bandwidth over 90% absorptance is as wide as 5.02 THz from 1.11 THz to 6.13 THz. The absorption bandwidth can be adjusted by changing the conductivity of vanadium dioxide or the chemical potential of graphene. It is insensitive to small incident angles for both TE and TM polarizations. The physical mechanism of the absorber is analyzed in details by the impedance matching theory and the electric field distributions of Ez. These results may have potential applications in the fields of modulators and tunable absorption devices.