Polarization-Controlled Dynamically Tunable Electromagnetically Induced Transparency-Like Effect Based on Graphene Metasurfaces

In this paper, we theoretically and numerically demonstrate a polarization-controlled dynamically tunable electromagnetically induced transparency-like (EIT-like) effect based on graphene metasurfaces. The unit cell of metasurface is composed of a rectangular graphene ring placed between two parallel graphene strips, which can achieve tunable spectral responses in different polarization directions. And when the polarization angle of the incident light changes gradually from 0° to 90°, the number of transparent windows can be switched between 1 and 2. The theoretical calculations based on the coupled Lorentz oscillator models have an excellent agreement with the simulation results. The mechanism of the dynamical modulation is attributable to the near field coupling of resonator units. Moreover, we can significantly adjust the transparency windows of the EIT-like by changing the asymmetry parameter and the Fermi level of graphene. Also, the strong dispersion and tunable group delay accompanied with the transparency window can be achieved for slow light application. Our proposed graphene metasurface architecture provides a new platform of multi-controlled EIT-like system for applications in slow light, optical sensor and selective filter.