Multichannel Absorption Enhancement in Graphene Based on Metal-Photonic Crystal Hetero-Structure

Abstract

The multichannel enhanced absorption effect in monolayer graphene is investigated. The proposed absorber is composed of a monolayer graphene sandwiched between a metal film and an asymmetric photonic crystal. A narrow absorption channel with absorbance above 88% at the near-infrared wavelength is realized, which is attributed to the Tamm plasmon polaritons (TPP). The electric field intensity distributions are calculated to provide an intuitive physical understanding of this multi-band absorption phenomenon. Moreover, the channel number of absorptions can be adjusted by controlling the period of the photonic crystal, which should be interesting for practical application. Besides, the dependence of the absorption performance on the structural dimensions is investigated detailedly to direct the subsequent production of the designed absorber. Our results have great value in applications for developing novel graphene-based tunable devices.