宽波段凸面闪耀光栅优化设计

凸面闪耀光栅是研制高光谱分辨率成像光谱仪的关键元件之一，一般凸面闪耀光栅的有效波段范围较窄，较难满足宽波段成像光谱仪对光栅衍射效率的需求。为拓宽仪器观测波段，对其中凸面闪耀光栅进行了优化设计。以0.4~2.5 m波段Offner型成像光谱仪为例，研究了凸面光栅单衍射级和双衍射级共路两种色散结构，采用分区闪耀光栅和双角闪耀光栅来提高宽波段范围内的衍射效率。优化设计了两种双闪耀光栅在不同色散结构下的槽形，用标量理论和有限元分析等方法对光栅衍射效率进行了计算。结合仪器信噪比，给出了满足成像光谱仪不同需求时所适用的光栅。

Design and optimization of broadband convex blazed grating

Convex blazed grating is one of the key elements in hyperspectral imaging spectrometers. Generally, the effective wavelength coverage of blazed grating is not broad enough to meet the need of imaging spectrometer for grating's diffraction efficiency. To extend the observation band of imaging spectrometer, in which the convex blazed grating was designed and optimized. A case study of 0.4-2.5 m band Offner type imaging spectrometer, single-order and dual-order dispersive structures of convex grating were researched. Partitioned blazed grating and dual-angle blazed grating were used to improve the diffraction efficiency in the range of a broadband. The groove shape of two types of dual-blazed gratings with different dispersive structures was optimally designed, and the diffraction efficiency was calculated by the method of scalar theory and finite element analysis. According to the signal-to-noise ratio(SNR) of the instrument, different types of grating were proposed to meet different requirements of imaging spectrometer.