Tuning control of dual-band terahertz perfect absorber based on graphene single layer

A dual-band graphene tunable terahertz metamaterial absorber is designed and numerically analyzed in this paper. The tunable absorber consists of two sizes of graphene square rings and a copper strip layer separated by a silicon dielectric layer in a unit cell. The simulation results demonstrate that the absorption performance of the terahertz absorber can be achieved by combining the absorption peaks induced by different graphene square rings. The absorber can achieve the absorption peaks of 99.8% and 99.9% at 0.74 THz and 1.71 THz, respectively. By changing the Fermi energy EF of the graphene material through modulating the bias voltage, the absorption and spectral position of the proposed absorber can be tuned. The flexible and easy design of the proposed single-layer graphene absorber makes it easier to be used in various metamaterial applications including sensing, imaging and communication.