以多层介质膜或金属膜为基底的脉冲压缩光栅在利特罗角附近使用,具有衍射效率高、衍射光谱带宽等特点,需要对其衍射光谱进行高分辨率的准确测量,以便为其制作工艺的改进提供可靠依据。根据双光路测量原理,建立了衍射光栅高分辨率光谱测量技术和实验装置。重点阐述了双束光路设计消除光源波动和杂散光对衍射效率测试结果影响的原理,通过光路改进解决了衍射光斑过大,且不能被光探测器完全收集的技术难点以及衍射光与入射光共路导致的探测器挡光问题。该装置可以测量宽带脉冲压缩光栅各级次的反射衍射光谱和透射衍射光谱,也可以测量在固定波长处的衍射角谱分布。目前的衍射光谱测试分辨率为1nm,角谱分辨率为0.2°。采用该装置测量了脉冲压缩光栅样品的光谱与角谱,在衍射效率超过90%的770~870nm的衍射带内,多次测量的平均相对偏差小于1.0%,可能的测量误差小于2.2%。 Pulse compression grating based on multi-layer dielectric film or metal film is used near Littrow angle, which has the characteristics of high diffraction efficiency and wide diffraction spectrum bandwidth, so its diffraction spectrum needs to be accurately measured with high resolution Process improvement to provide a reliable basis. According to the principle of double optical path measurement, a high-resolution diffraction grating spectroscopy measurement technology and experimental device were established. The principle of eliminating the fluctuation of light source and the influence of stray light on the diffraction efficiency test results is mainly described. The technical difficulties of diffractive light spot being too large and unable to be completely collected by the photodetector, Road led detector light blocking problem. The device can measure the reflection diffraction spectrum and the transmission diffraction spectrum of each stage of the broadband pulse compression grating, and can also measure the distribution of the diffraction angle spectrum at a fixed wavelength. The current diffraction spectrum test resolution of 1nm, angular resolution of 0.2 °. The apparatus was used to measure the spectrum and angular spectrum of pulse compression grating samples. The average relative deviation of multiple measurement was less than 1.0% and the possible measurement error was less than 2.2% in the diffraction band of 770 ~ 870nm with the diffraction efficiency over 90%.