本文设计了一种基于空气圆盘串的二维表面等离子体光栅光吸收器,采用二维时域有限差分法(2DFDTD)对该吸收器的平均吸收率随其几何结构参数的依赖关系进行了分析。结果表明:在可见光波段,空气圆盘串上圆盘的层数对该吸收器的吸收效果有较大的影响,层数越多,吸收效果越好。在层数一定的情况下,圆盘的半径、相邻圆盘串之间的中心距离、同一圆盘串上相邻圆盘的圆心之间的距离,相互影响,相互牵连。通过对吸收特性的优化,给出了优化结构参数。这种表面等离子体光栅光吸收器可应用于薄膜太阳能电池、传感器、滤波器、成像、热辐射和探测等多个领域。 In this paper, a two-dimensional surface plasmon grating optical absorber based on an air disk train was designed. The dependence of the average absorptance of the absorber with its geometrical parameters was studied by using two-dimensional finite difference time domain (2DFDTD) analysis. The results show that the number of disks on the air disc string has a significant influence on the absorbency of the absorber in the visible wavelength range. The more the number of layers, the better the absorption effect. In the case of a certain number of layers, the radius of the disc, the center distance between adjacent disc strings, and the distance between the centers of adjacent discs on the same disc string influence and mutually implicate each other. By optimizing the absorption characteristics, the optimal structural parameters are given. Such surface plasmon grating light absorbers can be used in many fields such as thin-film solar cells, sensors, filters, imaging, thermal radiation and sounding.