Dual-band, high sensitivity, angle-insensitive graphene-Perfect absorber based on surface plasmon resonance

We propose a perfect absorber of dual-band, high sensitivity and angle-insensitive based on surface plasmon polaritons (SPP) in monolayer graphene. The structure is composed of the metamaterial and graphene with stable performance. The absorption properties of the structure are theoretically investigated by simulation. Perfect absorption is achieved in the laser band range of 10.6 pm and the mid-infrared range of 7.54 pm. At the same time, the absorption peaks can be tuned by adjusting the structural parameters and the Fermi energy level of the graphene. In the simulation, the absorption performance of this structure is insensitive to angles, where both of the absorption peaks remain 95 % in the incident angle range of 0- 50 degrees. Moreover, the refractive index sensitivity of M1 and M2 can reach 3000 nm/RIU and 2000 nm/RIU, respectively. This research provides an effective solution for the development of mid-infrared optical devices and compatible camouflage application based on graphene.