In this paper, a structure based on metal-graphene-insulator–metal (MGIM) is designed as a tunable plasmonic perfect absorber (PPA) in the FIR-band range. Simulation results performed with the 3D finite difference time domain (FDTD) method show that in the perpendicular incidence of a plane wave light in the range of 35 to 105 µm, the absorption spectrum of the proposed device has a resonance peak with absorption above 95%, which can show excellent tunability by applying a gate bias voltage to the graphene nanolayers in the structure. In our proposed structure unit cell, there is a C₁ graphene nanolayer in the center and a C₂ graphene nanolayer around it that bias voltage is applied only to C₂, then changing the chemical potential of the two graphene nanolayers relative to each other, the absorption spectrum of the device shifts in the desired wavelength range.

在本文中，基于金属-石墨烯-绝缘体-金属（MGIM）的结构被设计为FIR波段范围内的可调等离激元完美吸收体（PPA）。用3D时差有限差分法（FDTD）进行的仿真结果表明，在平面波光的垂直入射范围为35至105 µm的情况下，该器件的吸收光谱具有共振峰，吸收率超过95％可以通过向结构中的石墨烯纳米层施加栅极偏置电压来显示出色的可调性。在我们提出的结构单元中，在中心有一个C ₁石墨烯纳米层，在其周围有一个C ₂石墨烯纳米层，仅向C ₂施加了偏置电压。然后，改变两个石墨烯纳米层彼此的化学势，器件的吸收光谱在所需的波长范围内移动。