Polarization-insensitive thin-film absorber is proposed by right-angled triangular grating. Combining the electric field distribution under two polarizations, the physical mechanism of absorption is analyzed using the finite element method. The presented results show that the average absorption efficiency exceeds 90.10% with a spectral range of 300-680 nm, and the incident angle can reach 50°. Compared with reference planar and triangular structures, the thin-film visible absorber presented has better absorption characteristics. Furthermore, compared with the reported visible absorber by rectangular grating, the visible absorber designed in this work has enhanced absorption spectrum bandwidth of 380 nm and wide angle of 50°. It is believed that the novel absorber has great potential in the field of visible light absorber.

偏振不敏感的薄膜吸收器是由直角三角形光栅提出的。结合两个极化下的电场分布，利用有限元方法分析了吸收的物理机理。结果表明，在300-680 nm的光谱范围内，平均吸收效率超过90.10％，入射角可以达到50°。与参考平面和三角形结构相比，本发明的薄膜可见吸收剂具有更好的吸收特性。此外，与报道的矩形光栅可见光吸收器相比，这项工作中设计的可见光吸收器具有增强的380 nm吸收光谱带宽和50°广角。据信，该新型吸收剂在可见光吸收剂领域具有巨大的潜力。