Anderson localization of light in disordered superlattices containing graphene layers

TL;DR

This paper explores how graphene layers in disordered superlattices influence light localization, deriving an analytic expression for localization length and revealing graphene's role in modulating Anderson localization effects.

Contribution

It provides a new analytic formula for localization length in graphene-based disordered superlattices and demonstrates graphene's impact on light localization behavior.

Findings

Graphene can significantly suppress delocalized modes.

Localization length exhibits periodic dependence on frequency.

Analytic expression for localization length matches numerical simulations.

Abstract

We theoretically investigate light propagation and Anderson localization in one-dimensional disordered superlattices composed of dielectric stacks with graphene sheets in between. Disorder is introduced either on graphene material parameters ({\it e.g.} Fermi energy) or on the widths of the dielectric stacks. We derive an analytic expression for the localization length $\xi$, and compare it to numerical simulations using transfer matrix technique; a very good agreement is found. We demonstrate that the presence of graphene may strongly attenuate the anomalously delocalised Breswter modes, and is at the origin of a periodic dependence of $\xi$ on frequency, in contrast to the usual asymptotic decay, $\xi \propto \omega^{-2}$. By unveiling the effects of graphene on Anderson localization of light, we pave the way for new applications of graphene-based, disordered photonic devices in the THz spectral range.