Analysis of extrinsic chirality in layer by layer structures distributed in non-planar unit-cell arrangements at microwave frequencies

Abstract

In this communication, the authors study the behavior of a chiral metamaterial designed to modify the polarization state of the incident plane wave that impinges obliquely on the metamaterial unit cells. The novelty of this work lies on how the unit cells are arranged along the metamaterial. The analysis of the behavior of these metamaterials has been done using the commercial 3D EM simulator Keysight EMPro using the finite difference time domain technique. Thanks to this software, two different arrangements have been studied: the sawtooth profile and the zigzag profile. In both distributions, the mutual twist rosette is implemented to combine intrinsic chirality, controlled by the mutual twist angle, and extrinsic chirality, controlled by the tilt angle of the arrangements. This combination shows an improvement of the optical activity and/or circular dichroism.