Design of a tunable dual-band terahertz absorber based on graphene metamaterial

摘要

Based on the tunable electrical and optical properties of graphene, we propose a tunable dual-band graphene-based metamaterial terahertz (THz) absorber. It successively consists of two layers of graphene-ring arrays and a metal ground plate separated by two dielectric layers. Simulation results indicate that either of the absorber's two absorption bands can be tuned over a broad frequency range while the other absorption band remains unchanged. The designed tunable structure can readily achieve perfect absorption at nearly any two frequency bands dynamically in the THz regime with wide incidence angle and polarization independence. It can find potential applications in photodetectors, solar cells, coherent thermal emitters, and microbolometers.