杂光测量是光学系统杂光分析的有效途径之一, 它能够对消杂光设计结果进行准确的评估。针对空间光学系统的工作环境, 考虑到其视场外有强烈辐射源(如太阳等), 采用点源透过率方法来验证光学系统抑制杂光的能力。搭建了一套无中心遮挡的离轴抛物面反射式杂光测量装置, 测量动态范围为10-1~10-11。利用该装置对口径为300mm、全视场为1.5°的卡塞格林式空间望远系统进行了实验测量, 给出了测量步骤和测量结果, 并分析了测量不确定度。该装置具有动态范围大、结构紧凑、出光口径大、准确度高(当置信概率为95%时, 测量不确定度约为1.48%)等优点, 可满足空间光学系统杂光测量的工程需要。

Measurement is an efficient approach to analyze the stray light in optical systems, which can evaluate the design results of restraining stray light accurately. For the special work condition of space optical systems, the intense radiant point sources (such as the sun, etc) outside of the field of view are considered. The method of point source transmittance (PST) is employed to validate the capability of restraining stray light. A suit of reflective parabolic stray light measuring device is set up, which is off axis without centered obstruction, and the measuring range is 10-1~10-11. The stray light of a Cassegrain space optical system with calibre 300mm, field of view 1.5° is measured. The measurement procedure and results are presented, and the uncertainty of measurement is analyzed. The results show that this device has large dynamic range, compact structure, large calibre of outlet light, highly accuracy (when the fiducial probability is about 95%,the uncertainty of measurement is about 1.48%) and so on, so it can meet the engineering requirement for stray light measurement of space optical systems.