Asymmetric transmission of linearly polarized light at optical metamaterials

TL;DR

This paper reports the experimental realization of a 3D chiral optical metamaterial that exhibits asymmetric transmission of linearly polarized light, supported by a theoretical framework for analyzing transmission matrices in complex media.

Contribution

It introduces a novel 3D chiral metamaterial design and provides a systematic analysis method for asymmetric transmission in complex, lossy media.

Findings

Demonstration of asymmetric transmission for linearly polarized light

Development of a criterion for asymmetric transmission in arbitrary polarization bases

Analysis showing polarization eigenstates do not obey fixed relations in such media

Abstract

We experimentally demonstrate a three-dimensional chiral optical metamaterial that exhibits an asymmetric transmission for forwardly and backwardly propagating linearly polarized light. The observation of this novel effect requires a metamaterial composed of three-dimensional chiral metaatoms without any rotational symmetry. Our analysis is supported by a systematic investigation of the transmission matrices for arbitrarily complex, lossy media that allows deriving a simple criterion for asymmetric transmission in an arbitrary polarization base. Contrary to physical intuition, in general the polarization eigenstates in such three-dimensional and low-symmetry metamaterials do not obey fxed relations and the associated transmission matrices cannot be symmetrized.