Circular dichroism of metasurfaces based on resonators with different N-fold rotational symmetry

摘要

Metasurfacc with periodic subwavelcngth resonators, placed on dielectric substrate is one of the main research interests in the terahertz (THz) photonics. Based on mctal/graphene hybrid materials such structures can achieve giant tunable asymmetric transmission and circular dichroism (CD). In this paper we discuss a circular dichroism of metasurfaces consisted of resonators with n-fold rotational symmetry C_n, i.e. C_2, C_3, C_4. The numerical simulation was performed using CST Microwave Studio. Theoretical analysis combines symmetry restrictions in effective polarizability approximation for calculation of transmission and reflection coefficients. The numerical simulation was done in the millimeter wave range. This research has both fundamental and applied relevance, and may be used in development of terahertz and microwave devices, such as waveplates, polarization sensitive absorbers, etc.