Tunable multi-narrowband perfect absorber based on graphene and black phosphorus metamaterial

Abstract

Black phosphorus (BP) and graphene are two-dimensional (2D) metamaterials that support surface plasmon resonance. We propose a tunable mid-infrared multi-narrowband perfect absorber based on graphene and BP metamaterial. Perfect absorption peaks can be explained by the interference of two excited states in the structure. The transfer characteristics of the system are calculated by the coupled mode theory (CMT), and the theoretical calculated results agree well with the finite-difference time-domain (FDTD) numerical simulated ones. The resonant positions of the absorption peaks are affected by the layer spacing. By changing BP carrier density and graphene Fermi level, the dynamic tunable function can be realized, and the absorption performance of the system is not affected within the adjustment range. Meanwhile, the absorption performance of the system is not insensitive to the polarization angle of the incident light, when the polarization angle is less than 30°. The designed system can be applied to a variety of optical devices, including plasma sensors, multi-frequency absorbers, reflectors, switching controllers and filters.