Terahertz symmetrical polarization conversion in asymmetrical chiral metasurface

A linearly and circularly reflective polarization converter (RPC) using bilayer unidirectional asymmetry electric inductive-capacitive (UAELC) chiral metamaterial (CMM) is theoretically demonstrated. By normally illuminated by a linear polarized (LP) incidence on front side or back side of the proposed CMM, backward 90° polarization rotation with cross polarization conversion (CPC) ratio of over 99% is achieved, meanwhile it ensures a nearly pure cross polarization conversion of circularly polarized (CP) wave. The excellent chiral functionality is due to the cross coupling between the induced magnetic field and incident electric field among the UAELC-dimer. The novel CMM may greatly benefit potential applications including scanning antenna, modulator, and detector inTHz to infrared regions.