A novel tunable terahertz wave modulator based on graphene and frequency selective surface (FSS)

Abstract

In this paper, a high-performance modulator based on FSS and double layers graphene has been designed and numerically investigated. The proposed structure is composed of graphene, dielectric, FSS, dielectric and graphene. The amplitude of terahertz signal which transmit from the modulator can be dynamically controlled by the graphene, and the FSS is used to enhance the light-matter interaction in graphene. The advantages of the proposed modulator are high modulation depth and a broad bandwidth. The maximum modulation depth can reach 100%, and the modulation depth can reach more than 90% even if the wavelength ranges from 500 um to 1300 um (0.23 THz to 0.6 THz). Moreover, the performance is demonstrated by the equivalent circuit theoretically. The numerically results are in well agreement with equivalent circuit results. The proposed modulator shows enormous potential in terahertz imaging and communications systems.