斜入射下双波段双层衍射光学元件优化设计与分析

Based on the normal working mode of a diffractive optical element (DOE) under oblique incidence, a mathematical model about the effects of incident angle and wavelength on the diffraction efficiency of a dual-band double-layer DOE under oblique incidence is established, and the optimal design of the double-layer DOE is presented. By optimizing the design wavelength pair within the incident angle range, the microstructure height of the double-layer DOE is calculated and the high diffraction efficiency of double-layer DOE under oblique incidence is realized, which makes up the defects in the double-layer DOE, guides the design of the dual-band hybrid imaging system, and can be extended to the design of a multi-band multi-layer DOE. Based on this method, a hybrid middle/long dual-band infrared optical system is designed. The results show that compared with the conventional method, it possesses a more reasonable design theory and a better design result.