Optical modulated graphene metamaterial based on plasmon-induced transparency in the terahertz band: Application for sensing

We design a graphene metamaterial composed of graphene strips and graphene rings in the terahertz (THz) band. The graphene metamaterial can excite plasmon-induced transparency (PIT) by destructive interference between the super-radiation and the sub-radiation. This PIT phenomenon can be effectively modulated by adjusting the Fermi level of the single graphene structure and carrier mobility of the graphene. Then we establish a two-particle model to verify the correctness of the CST simulation. The final fitting effect is satisfactory. Besides, the metamaterial exhibits excellent sensing properties. The results show its Q factor, the sensitivity, and the figure of merit (FOM) can reach 40.52, 1.4 THz/RIU (Refractive Index Unit), and 17.30 RIU−1 respectively. In addition, the group delay near the PIT window can reach 1.1 ps when EF = 1 eV. Therefore, this design may play an extremely pivotal role and reference for the future development of the terahertz graphene-based functional metamaterial.