光栅的多级衍射杂散光对空间外差拉曼光谱仪的成像质量具有重要影响。为了提高其成像质量,使光谱特征更准确,针对空间外差拉曼光谱仪中光栅产生的多级衍射杂散光进行分析与抑制研究。依据光学传递理论,利用ASAP软件对空间外差拉曼光谱仪中光栅产生的多级衍射杂散光进行仿真与分析,利用挡板、光阑和光学陷阱等方法设计了能够抑制-2.5°~2.5°视场范围内杂散光的结构。结果表明:光栅产生的多级衍射杂散辐射比由4.996×10 ^-3降到了1.57×10 ^-8,设计的结构对空间拉曼光谱仪系统内因光栅产生的多级衍射杂散光具有良好的抑制效果,有效提高了系统的成像质量。

Stray light resulting from grating multistage diffraction influences the imaging quality of the spatial heterodyne Raman spectrometer (SHRS). In this study, the stray light was analyzed and controlled to enhance the precision of the SHRS. The optical transmission theory was employed to study the stray light produced by grating multistage diffraction in the SHRS using the ASAP software; a stray light controlling structure was designed in -2.5°-2.5° field-of-view via baffling, beam stopping, and light trapping. The results indicate that the stray light ratio of multistage diffraction is reduced from 4.996×10 -3 to 1.57×10 -8. Thus, the developed structure can efficiently control the stray light from grating multistage diffraction and improve the imaging quality of the SHRS.