Sensitive perfect absorber with monolayer graphene-based multi-layer dielectric grating structure

We propose a simple structure based on monolayer graphene with two layers dielectric grating. The effect of structural parameters on the optical behavior is studied by using the rigorous couple wave analysis method. The situation of changing incident angle for TM polarization is considered without changing the geometrical parameters. The absorption of about 77% and the Q-factor value of about 3390 can be obtained. In order to enhance absorption, we further design perfect absorption based on monolayer graphene with multiple-layer dielectric grating structure. The guide-mode resonances of both the grating and the dielectric layers are excited to achieve perfect multi-peak absorption. The proposed structure uses relatively less layers to achieve the perfect absorption, which can provide a reference for the further development of high sensitive modulators.