Tunable Circular Polarization Detection and Full Stokes Measurement Structure

Measuring the polarization state of light is an inherent problem, especially for the detection of circularly polarized light. We propose a metasurface structure based on graphene to investigate the circular polarization detection function in the THz regime by using the finite difference time domain (FDTD) method. The proposed graphene metasurface consists of a layer of graphene arrays, a polymer dielectric spacer, and a layer of graphene bands. By adjusting the Fermi energy, the structure can realize tunable polarization detection functions. On this basis, we combine tunable filters with different angles into the structure to achieve full Stokes parameter measurement. The simulation results show that the structure's working band can be tuned in the range of 25.88 μm-28.68 μm. The structure we designed helps to develop a tunable and integrated polarization detection method.