Dynamically tunable plasmon-induced transparency effect based on graphene metasurfaces

Plasmon-induced transparency (PIT) is theoretically explored for a graphene metamaterial using finite-difference time-domain numerical simulations and coupled-mode-theory theoretical analysis. In this work, the proposed structure consists of one rectangular cavity and three strips to generate the PIT phenomenon. The PIT window can be regulated dynamically by adjusting the Fermi level of the graphene. Importantly, the modulation depth of the amplitude can reach 90.4%. The refractive index sensitivity of the PIT window is also investigated, and the simulation results show that a sensitivity of 1.335 THz RIU-1 is achieved. Additionally, when the polarization angle of the incident light is changed gradually from 0 degrees to 90 degrees, the performance of the structure is greatly affected. Finally, the proposed structure is particularly enlightening for the design of dynamically tuned terahertz devices.