PROJECT TITLE :

Enhancement of Absorption in Graphene Strips With Cascaded Grating Structures

ABSTRACT:

The enhanced absorption effects of graphene strips with cascaded grating structures are investigated. A graphene absorber, that consists of a graphene grating and a dielectric grating backed with a Bragg grating, is designed and studied. The combined effects of guided-mode resonances with dielectric gratings and therefore the photonic bandgap with a Bragg grating result in the conclusion of critical coupling, that makes the absorber exhibit close to-unity absorption/emission at resonance however with ultra-slender spectral and antennalike responses. Each the coupled-mode theory and the electrical-field distributions are presented to produce a physical understanding of such an absorption behavior. We believe that the conclusions could be helpful for the planning of graphene-based optoelectronic devices.