狭缝高度对单色仪光谱分辨率的作用及验证

单色仪广泛应用于光谱定标、物质分析等方面，高光谱分辨率单色仪系统的研究具有重要意义。本文基于矢量光栅方程推导考察了入射狭缝高度对光谱仪器谱线弯曲的影响程度，给出了谱线弯曲同波长、狭缝高度的解析表达式，进而提出了一种基于狭缝高度抑制谱线弯曲的单色仪光谱分辨率优化方案。方法：结合高灵敏度、超快时间响应探测器的性能指标要求，设计了一款光谱分辨率为0.1 nm，波段范围为185 nm~900 nm 的三光栅单色仪光学系统，并搭建样机验证狭缝高度对谱线弯曲的影响，探究狭缝高度对光谱分辨率的影响规律。结果：实验结果表明：在狭缝宽度一定时，对狭缝高度进行优化，可将光谱分辨率从0.32 nm 提高至0.1 nm。结论：狭缝高度会对光栅单色仪的光谱分辨率产生影响，实验结果可为单色仪的使用提供参考。

Monochromators are widely used in spectral calibration, material analysis and other related fields. The research on high-spectral-resolution monochromator systems is of great significance. Based on the derivation of the vector grating equation, this paper investigates the degree of influence of incident slit height on the spectral line curvature of spectroscopic instruments, and derives the analytical expressions of spectral line curvature in relation to wavelength and slit height. Furthermore, a monochromator spectral resolution optimization scheme for suppressing spectral line curvature based on slit height is proposed. Methods: In line with the performance index requirements of high-sensitivity and ultrafast time-response detectors, a three-grating monochromator optical system with a spectral resolution of 0.1 nm and a wavelength range of 185 nm to 900 nm was designed. A prototype was constructed to verify the effect of slit height on spectral line curvature and explore the influence regularity of slit height on spectral resolution. Results: The experimental results demonstrate that when the slit width is fixed, optimizing the slit height can increase the spectral resolution from 0.32 nm to 0.1 nm. Conclusion: The slit height has a significant impact on the spectral resolution of grating monochromators, and the experimental results can provide valuable references for the application of monochromators.