宽光谱大视场角的高衍射效率多层衍射元件

Multilayer Diffraction Element with Wide Field of View and High Diffractive Efficiency

提出一种新颖的多层衍射元件(MLDOE),由具有不同折射率和色散性质的光学材料构成,第一层和最后一层为高折射率低色散和低折射率高色散光学材料的组合,中间填充层为阿贝数较小的光学塑料。此MLDOE在最大光束全视场角为110°情况下,设计波段内的各个波长的衍射效率高达90%以上,可有效提高折-衍混合光学系统的能量利用率,提高成像质量。

A novel multilayer diffractive optical element （MLDOE） composed with different optical materials is investigated and the materials combination principle is discussed. The results show that the first layer, the last layer and the middle layer should be high refractive index and low dispersion optical material, low refractive index and high dispersion optical material, and smaller Abbe number optical material, respectively. The diffractive efficiency of the MLDOE at each wavelength in designed band is larger than 90% and the full angle of view can reach 110°, which can effectively improve energy utilization ratio and image quality of the hybrid refractive-diffractive optical system.