A Tunable Terahertz Graphene Metamaterial Sensor Based on Dual Polarized Plasmon-Induced Transparency

We present a terahertz graphene metamaterial sensor based on dual polarized plasmon-induced transparency caused by the destructive interference between the bright mode and the two quasi-dark modes in the terahertz (THz) band. In addition, the sensor can achieve frequency modulation by adjusting the polarization direction of the THz wave and the Fermi level of graphene. Importantly, the sensor also has high sensitivity at each polarization direction, and the sensitivity of dual transmission peaks with x-polarization direction can reach about 1.1 THz/RIU (Refractive Index Unit). Furthermore, the theoretical results of the proposed three-particle model are in good agreement with the simulated transmission spectra. The sensor is also insensitive to the change of incident angles, and the transmission spectra of the sensor can remain roughly unchanged with the incident angle less than 60°, which is beneficial to the high-speed and high-sensitivity detection in a complex environment. Therefore, the proposed graphene metamaterial sensor exhibits numerous potential applications in THz biochemical sensing.