为获得激光装置密闭空间内部气溶胶分布变化情况，提出了一种基于微纳光纤传感的密闭空间气溶胶检测方法。首先通过理论计算微纳光纤表面吸附气溶胶后传输能量的变化情况，得到能量损耗与气溶胶折射率、尺度之间的关系。利用火焰熔融扫描拉锥法拉制微纳光纤，并放置在激光装置中实验验证。实验结果表明：利用直径为1.5 μm的微纳光纤可以有效检测密闭空间内直径为1 μm和2 μm尺度的颗粒污染物，并可以通过微纳光纤的附加损耗评估颗粒污染物的数量及尺寸，得到附加损耗与空间环境洁净度之间的关系，且理论与实验结果符合较好。

To obtain the number and sizes of aerosols generated in the enclosed room of high power laser system, a method of microparticle detection with microfiber was demonstrated in enclosed room. The additional loss of microfiber, caused by adhered microparticles with different refractive indices and diameters, were researched and simulated based on the evanescent field theory. Microfibers were fabricated using hydrogen-oxygen flame-heated scanning fiber drawing method and placed in the high power laser facility for demonstration. The experimental results show that, 1 μm- and 2 μm-diameter contamination particles were detected by 1.5 μm-diameter microfiber. The diameter and the number of microparticle can be estimated by measuring the additional loss of the sensing unit. The relation between the additional loss and space environment cleanliness can be obtained. The simulated results agree well with the experimental results.