Graphene-based tunable coding metasurfaces in terahertz band

Abstract

Two graphene-based tunable coding metasurfaces are proposed for beam steering in terahertz band. The coding metasurfaces are composed of the unit cell with a sandwich-like structure, which contains the top layer of anisotropic rectangular graphene structure, intermediate dielectric layer and ground plane. The designed metasurfaces can be dynamically adjusted since the characteristics of unit cell are changed by the chemical potential of graphene. When the relaxation time and chemical potential of graphene are 0.8 ps and 0.85 eV, respectively. The coding metasurfaces could realize beam steering in 1.30 THz-1.70 THz. On the other hand, when the chemical potential of graphene is 0 eV, two metasurfaces without beam steering in this band. The designed graphene-based tunable coding metasurfaces has potential application value in the fields of terahertz communication, sensing, etc.