设计了一种槽深呈线性渐变的表面等离子光栅光吸收器, 运用有限元算法分析了该吸收器的结构参数及光入射角度对其在可见光波段内的吸收性能的影响, 并与槽深呈对称分布的光吸收器进行了对比。结果表明, 增加空气凹槽的数目、宽度和深度以及减小相邻凹槽间距, 均可有效提高光吸收率。与槽深呈对称分布的光吸收器相比, 该吸收器的吸收性能更优越。

A new kind of optical absorber based on surface plasmonic gratings with depth-linear-gradient grooves is designed. The effects of structural parameters and the light incident angle on the absorption characteristics within the visible wavelength range are analyzed by the finite element method. The proposed optical absorber is also compared with other optical absorbers with symmetrical groove depths. Results indicate that, increasing the number of grooves, groove width, and groove depth of air grooves, as well as reducing the center distance of adjacent air grooves, all can effectively enhanced the light absorption efficiency. The absorption performance of optical absorber here is superior to that of other optical absorber with symmetrical groove depth.