Dual-Band Polarization-Sensitive Graphene Chiral Metasurface and its Application as a Refractive Index Sensor

The asymmetric transmission has fascinated wide interest because of its novel applications. In this paper, we propose and present the design procedure and the simulation results of the tunable dual-band polarization-sensitive graphene chiral metasurface. The resonance wavelength depends on and is controlled by the graphene chemical potential. The two-dimensional chiral response of the structure, circular conversion dichroism (CCD), is tunable and is reached to 0.2. As an application of the tunable chiral structure, a novel tunable polarization-sensitive refractive index sensor with the maximum sensitivities of 7000-10000 nm/RIU is proposed and analyzed. For different kinds of the circularly polarized incident electromagnetic waves, the sensitivities are high and noticeable. This paper exposes a new way to propose other polarization-sensitive structures, such as switches and absorbers in the terahertz (THz) region. In addition, the proposed structure and its application could be useful in polarization-sensitive devices and systems.