Highly efficient narrow-band absorption of a graphene-based Fabry–Perot structure at telecommunication wavelengths

Abstract

We numerically investigate a novel and competitive graphene-based Fabry-Perot (GFP) structure to enhance the light-matter interaction of graphene at telecommunication wavelengths, and highly efficient narrow-band absorption is achieved. The absorptance of the GFP structure can reach near-unity by optimizing the position of graphene in the dielectric layer, and the localized absorptance of graphene at telecommunication wavelengths can be improved from 2.3% to 83.2%, which is attributed to the strong field confinement of Fabry-Perot resonance in the dielectric layer. The remarkable enhancement of graphene absorption can be acquired for both TM and TE polarizations. Such a graphene-based structure enables a tunable operating wavelength by adjusting geometrical parameters to realize the spectral selectivity of the system in the near-infrared range. Furthermore, the optimized GFP structure possesses excellent spectral selectivity with the full width at half-maximum of 33 nm. The meaningful improvement and tunability of graphene absorption can provide a promising prospect for the realization of high-performance graphene-based optoelectronic devices.