论文部分内容阅读
凹面衍射光栅兼具色散分光与光束聚焦功能,同时具有像差校正、低杂散光、无鬼线和高信噪比等优势而受到光谱仪器领域的广泛关注。衍射效率作为凹面光栅最重要的技术指标之一,其测量技术水平逐渐成为光谱仪器行业最为关注的课题之一。传统方法一般采用双单色仪结构实现凹面光栅衍射效率的测量,该方法主要存在两方面问题,一是测量标准反射镜和待测光栅的出射光谱带宽不同,二是光栅叠级、杂散光的影响;上述问题的存在降低了高性能凹面光栅衍射效率测量的准确性。本文提出了一种基于傅里叶光学原理测量凹面光栅衍射效率的新方法;针对该方法建立了凹面光栅衍射效率测量的数学模型,并采用光学追迹和傅里叶光学方法相结合对其进行了仿真分析,从而验证了该方法的正确性;针对动镜横移误差、倾斜误差、光源稳定性、动镜运动距离误差等因素影响凹面光栅衍射效率测量精度的问题,提出引入辅助探测器的方法来进一步提高衍射效率测量精度,并对有无辅助探测器情况下的上述误差对衍射效率的影响进行了数学推导和仿真分析,分析结果表明引入辅助探测器可以有效抑制了上述误差对凹面光栅衍射效率测量的影响。对比传统双单色仪测量方法而言,该方法不仅能够解决传统测量方法存在的问题,同时还具有多波长同时测量、高光通量、高分辨率、高波数精度等优势,可以有效提高凹面光栅衍射效率的测量精度和测量效率。
The concave diffraction grating combines the advantages of dispersion spectroscopy and beam focusing, and has the advantages of aberration correction, low stray light, no ghost line and high signal to noise ratio and is widely concerned by the spectrometer field. Diffraction efficiency, as one of the most important technical indexes of concave grating, has gradually become one of the most concerned topics in spectrometer industry. The traditional method generally adopts the double monochromator structure to measure the diffraction efficiency of the concave grating. There are mainly two problems in the method. One is that the standard spectral width of the exit mirror of the standard reflector and the grating to be measured is different, the other is the grating stack, stray light ; The existence of the above problems reduces the accuracy of the diffraction efficiency measurement of high-performance concave grating. In this paper, a new method of measuring diffraction efficiency of concave grating based on Fourier optics is proposed. A mathematical model of diffraction efficiency measurement of concave grating is established and combined with optical tracing and Fourier optics The simulation analysis is carried out to verify the correctness of the method. Aiming at the problem that the precision of the diffraction efficiency of the concave grating is affected by the factors such as the movement error of the moving mirror, the tilt error, the stability of the light source, the moving distance of the moving mirror, Method to further improve the measurement accuracy of the diffraction efficiency, and the mathematical derivation and simulation analysis of the above-mentioned error on the diffraction efficiency with or without the auxiliary detector, the analysis results show that the introduction of auxiliary detector can effectively inhibit the above error on the concave grating Effect of diffraction efficiency measurement. Compared with traditional dual monochromator measurement methods, this method can not only solve the problems of traditional measurement methods, but also has the advantages of simultaneous measurement of multiple wavelengths, high luminous flux, high resolution and high wave number accuracy, which can effectively improve the diffraction of concave grating Efficiency of measurement accuracy and measurement efficiency.