Dual broadband absorber based on graphene metamaterial in the terahertz range

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. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement