Graphene-based absorber exploiting guided mode resonances in one-dimensional gratings

TL;DR

This paper presents a simple one-dimensional dielectric grating design that significantly enhances light absorption in monolayer graphene through guided mode resonances, achieving up to 60% absorption experimentally and 26-fold enhancement theoretically.

Contribution

It introduces a novel, scalable grating structure that boosts graphene's optical absorption via guided mode resonances, with both theoretical and experimental validation.

Findings

Achieves up to 60% light absorption at normal incidence.

Theoretical enhancement factor of about 26 over monolayer graphene.

Experimental absorbance peaks up to 40% over narrow bands.

Abstract

A one-dimensional dielectric grating, based on a simple geometry, is proposed and investigated to enhance light absorption in a monolayer graphene exploiting guided mode resonances. Numerical findings reveal that the optimized configuration is able to absorb up to 60% of the impinging light at normal incidence for both TE and TM polarizations resulting in a theoretical enhancement factor of about 26 with respect to the monolayer graphene absorption (about 2.3%). Experimental results confirm this behaviour showing CVD graphene absorbance peaks up to about 40% over narrow bands of few nanometers. The simple and flexible design paves the way for the realization of innovative, scalable and easy-to-fabricate graphene-based optical absorbers.