Bilayer terahertz chiral metasurfaces with different dihedral symmetries

Abstract

In this paper, we discuss the isotropic chiroptical response of two-layered metasurfaces with n -fold dihedral symmetries of resonators ( D n ) in the terahertz (THz) range. The analysis of numerical calculations is based on the homogenization model through effective polarizability approximation. We reveal the impact of resonator symmetry on circular dichroism and polarization anisotropy of the metasurface. In particular, it is shown that an increase in the symmetry order of a metasurface unit cell leads to a proportional resonance red shift in circular dichroism spectra. This research has both fundamental and applied relevance, and may enable the realization of THz devices capable of polarization manipulation or possessing polarization sensitive features.