Light propagation in quasiperiodic dieletric multilayers separated by graphene

TL;DR

This paper investigates how embedding graphene in Fibonacci quasiperiodic dielectric multilayers affects light propagation, revealing tunable omnidirectional photonic band gaps and polarization-independent effects.

Contribution

It introduces a transfer matrix approach to analyze graphene's impact on photonic band gaps in quasiperiodic multilayers, highlighting tunability via chemical potential.

Findings

Graphene reduces overall transmissivity and creates low-frequency transmission gaps.

Transmission is higher for TM polarization than TE.

Graphene-induced photonic bandgaps are omnidirectional and polarization-independent.

Abstract

The study of photonic crystals, artificial materials whose dielectric properties can be tailored according to the stacking of its constituents, remains an attractive research area. In this article we have employed a transfer matrix treatment to study the propagation of light waves in Fibonacci quasiperiodic dieletric multilayers with graphene embedded. We calculated their dispersion and transmission spectra in order to investigate the effects of the graphene monolayers and quasiperiodic disorder on the system physical behavior. The quasiperiodic dieletric multilayer is composed of two building blocks, silicon dioxide (building block A = SiO2) and titanium dioxide (building block B = TiO2). Our numerical results show that the presence of graphene monolayers reduces the transmissivity on the whole range of frequency and induces a transmission gap in the low frequency region. Regarding the polarization of the light wave, we found that the transmission coefficient is higher for the transverse magnetic (TM) case than for the transverse electric (TE) one. We also conclude from our numerical results that the graphene induced photonic bandgaps (GIPBGs) do not depend on the polarization (TE or TM) of the light wave nor on the Fibonacci generation index n. Moreover, the GIPBGs are omnidirectional photonic band gaps, therefore light cannot propagate in this structures for frequencies lower than a certain value, whatever the incidence angle. Finally, a plot of the transmission spectra versus chemical potential shows that one can, in principle, adjust the width of the photonic band gap by tuning the chemical potential via a gate voltage.