Elliptical dichroism: operating principle of planar chiral metamaterials

TL;DR

This paper explains how planar chiral structures can be modeled as biaxial elliptically dichroic crystals using a homogenization technique, revealing their unique optical properties like elliptical polarization eigenstates and asymmetric transmission.

Contribution

It introduces a homogenization approach based on Lorentz theory to describe planar chiral structures with an effective dielectric tensor, linking them to elliptically dichroic crystals.

Findings

Planar chiral structures exhibit co-rotating elliptical polarization eigenstates.

They show asymmetric, direction-dependent transmission for different polarizations.

The effective dielectric tensor characterizes their optical behavior.

Abstract

We employ a homogenization technique based on the Lorentz electronic theory to show that planar chiral structures (PCSs) can be described by an effective dielectric tensor similar to that of biaxial elliptically dichroic crystals. Such a crystal is shown to behave like a PCS insofar as it exhibits its characteristic optical properties, namely, co-rotating elliptical polarization eigenstates and asymmetric, direction-dependent transmission for left/right-handed incident wave polarization.