Anisotropic perfect absorber based on black phosphorus-graphene

Two-dimensional materials have garnered extensive attention in the realm of optical devices due to their unique physical properties. In this paper, we propose a tunable and anisotropic perfect absorber composed of anisotropic black phosphorus (BP) and isotropic graphene. The plasmon resonance of this anisotropic material and isotropic material achieves a strong anisotropic plasma response. The proposed structure demonstrates absorption of 99.73 % and 98.35 % in the x- and y-polarization directions, respectively. By adjusting the geometric parameters and the levels of doping with graphene and BP, the resonance characteristics can be effectively controlled. In addition, the robustness to incident angle and polarization sensitivity is also illustrated. Consequently, our research offers broad prospects for applications in polarization-selective and tunable high-performance devices, such as polarizers, modulators, and mid-infrared spectral imaging.