Planar metamaterial with transmission and reflection that depend on the direction of incidence

TL;DR

This paper demonstrates that planar chiral metamaterials exhibit direction-dependent transmission and reflection of circularly polarized waves, due to their asymmetric design causing polarization-sensitive resonant responses.

Contribution

It introduces a novel planar metamaterial design that shows asymmetric optical responses based on incidence direction and polarization handedness.

Findings

Reflection and transmission depend on incidence direction and polarization

The effect is resonant and linked to symmetry breaking in the metamaterial

Polarization-sensitive excitation of dipolar responses observed

Abstract

We report that normal incidence reflection and transmission of circularly polarized electromagnetic waves from and through planar split-ring metamaterials with chiral symmetry breaking depends on the incidence direction and handedness of circular polarization. The effect has a resonant nature and is linked to the lack of mirror-symmetry in the metamaterial pattern leading to a polarization-sensitive excitation of electric and magnetic dipolar responses in the meta-molecules.