Dual broadband absorber based on graphene metamaterial in the terahertz range

Abstract

In this paper, a dual broadband terahertz (THz) graphene metamaterial absorber (MA) is presented. The absorber consists of patterned graphene, a gating layer, and gold ground separated by a SiO2 substrate. Multiple resonances and broadband absorption are obtained simultaneously with a simple asymmetric electrical split ring structure. The numerical calculations indicate that there are two broad absorption bands (with an absorptance larger than 95%) from 1.4 THz to 1.9 THz and 4.5 THz to 5.1 THz, respectively. Under the regulation of the graphene chemical potential, the absorption strength can be controlled electrically from 95% to 10%. Furthermore, it possesses a good tolerance of polarization and incidence angles. The design scheme provides a new perspective to design dual broadband absorbers and is scalable to develop various graphene absorbers at other frequencies.