针对高能窄带激光系统对光谱纯度检测的需求,提出通过精确测量激光光谱能量分布情况分析光谱纯度的方法,并进行了相关实验研究。该光谱纯度检测装置主要由中阶梯光栅、精密移动刀口、灵敏功率计等组成,实验利用该装置分析了复合腔结构准分子激光系统输出激光的光谱纯度,实验结果表明通过精确测量激光中各光谱成分所占的能量比例可实现光谱纯度的检测。该光谱纯度检测装置结构紧凑、成本较低、测量准确度高,在高能窄带激光系统搭建过程中具有重要的应用价值。 In order to meet the demand of spectral purity detection in high-energy narrow-band laser system, a method of analyzing spectral purity by accurately measuring the energy distribution of laser spectrum is proposed and related experimental studies are carried out. The spectral purity detection device is mainly composed of a middle-stepped grating, a precision moving blade, a sensitive power meter and the like. Experiments are performed to analyze the spectral purity of the output laser of the laser in an optical system with an integrated cavity structure. The experimental results show that by accurately measuring each spectrum The proportion of the energy content of the composition can achieve spectral purity detection. The spectral purity detection device has the advantages of compact structure, low cost and high measurement accuracy, and has important application value in the process of building a high-energy narrow-band laser system.