Spectral shifts in the properties of a periodic multilayered stack due to isotropic chiral layers

TL;DR

This paper analyzes how isotropic chiral layers in a periodic multilayered stack cause spectral shifts in its properties, with potential applications in spectroscopy, by homogenizing the structure as a uniaxial bianisotropic medium.

Contribution

It introduces a homogenization approach for multilayered stacks with isotropic chiral layers and reveals how chirality induces spectral shifts in resonance frequencies.

Findings

Spectral shifts depend on the chirality parameter.

Resonance frequency can be shifted or sign-switched.

Homogenization as uniaxial bianisotropic medium is effective.

Abstract

Investigating the canonical problem of a periodic multilayered stack containing isotropic chiral layers, we homogenized it as a uniaxial bianisotropic medium and derived its effective constitutive parameters. The stack shows a resonant behavior, when its unit cell consists of a metallic layer and an isotropic chiral layer. The presence of isotropic chirality can result in small shifts of the resonance frequency for reasonably large values of the chirality parameter, implying that the sign of an effective permittivity can be switched. Such spectral shifts in the dielectric properties can be potentially useful for spectroscopic purposes.