Ultra-high sensitivity sensing based on tunable plasmon-induced transparency in graphene metamaterials in terahertz

Abstract

Abstract We investigate plasmon-induced transparency (PIT) and sensing characteristics in a simple graphene metamaterial through the finite-different time-domain (FDTD) simulation. The results indicate that PIT is caused by the destructive interference between two plasmonic modes in the crossed graphene structure. To effectively and dynamically tune the transmission spectrum of PIT, we can change positional parameters of vertical graphene sheet, and Fermi level, and polarization angle of plane-polarized light, respectively. In particular, when monolayer graphene is changed into two layers, single PIT transparent window splits into double induced transparent windows, and double PIT can also be dynamically tuned by the height h. Further, we also find that the sensitivity can reach up to 1.71345 THz/RIU, and figure of merit(FOM) can reach up to 6.998. The results may provide a new foundation for manufacturing a low-power, ultra-fast response, dynamically adjustable micro-nano sensor in terahertz.