一种非球面反射镜有效通光口径的定量化检测方法  

A Quantitative Testing Method for the Effective Clear Aperture of Aspheric Mirrors

作　　者：孟晓辉[1,2] 张继友 王永刚[1,2] 李昂 周于鸣[1,2] 李文卿 MENG Xiaohui;ZHANG Jiyou;WANG Yonggang;LI Ang;ZHOU Yuming;LI Wenqing(Beijing institute of space Mechanics&Electricity,Beijing 100094,China;Optical Ultraprecise Processing Technology Innovation Center for Science and Technology Industry of National Defense,Beijing 100094,China)

机构地区：[1]北京空间机电研究所,北京100094 [2]国防科技工业光学超精密加工技术创新中心(先进制造类),北京100094

出　　处：《航天返回与遥感》2020年第5期38-46,共9页Spacecraft Recovery & Remote Sensing

基　　金：国防科技创新特区项目(19-163-18-ZT-013-023-01)。

摘　　要：有效通光口径是非球面反射镜的一项重要指标参数,但在现有检测工艺中存在着难以定量化检测、测试误差大等问题,导致在后续系统复算过程中难以对成像品质进行正确评估。为了解决这些问题,文章提出在干涉检测阶段采用非线性误差校正的方法来对非球面反射镜的有效通光口径进行检测。首先是通过光线追迹的方法采集一系列干涉仪CCD坐标系和待测反射镜坐标系下的坐标点数据;然后对坐标点数据进行多项式函数拟合,建立两者间非线性误差函数关系;最后以干涉仪CCD坐标系尺度下的有效干涉条纹图形作为输入,反算出镜面尺度下反射镜的实际有效通光口径。在工程应用实例中,对某型号空间相机中的一块米级非球面反射镜进行了实际检测,单边测试精度为干涉仪1个像素所对应的镜面尺度误差,且该方法的测试误差主要取决于测试系统中所选用干涉仪CCD平均分辨率的大小;分别将校正前后的反射镜参数代入到系统中进行复算,光学系统调制传递函数MTF值的偏差达到了0.013@71.5线对/mm。结果表明,应用该方法不仅可以在加工过程中对反射镜的有效通光口径进行实时监测,还能正确评估相机地面装调阶段的光学系统成像品质,在空间光学元件先进制造领域具有重要的工程应用意义。The effective clear aperture is an important parameter of aspheric mirrors,but there were many problems existed such as the difficulty of quantitative testing and larger test errors.Then in the subsequent stage of ground installation and adjustment,it was often difficult to correctly assess the system imaging quality.In order to solve these problems,a testing method based on nonlinear correction was proposed.Firstly,different data were acquired in interferometer CCD and mirror coordination systems using the ray tracing method.Then the nonlinear relationship between the mirror under test and the surface map was established.Finally,the effective interference fringe pattern in the scale of the interferometer CCD coordinate system was used as the input to inversely calculate the actual effective aperture of the mirror under the mirror scale.A space camera primary mirror with diameter larger than one meter was tested using this method,which accuracy can reach 1 pixel corresponding mirror length,and the testing accuracy is mainly depended on the interferometer CCD average resolution.The optical system modulation transfer function was separately analyzed by taking the original and corrected maps,and the MTF value offset was 0.013@71.5lp/mm.The results show that it is useful to test the effective clear aperture timely in manufacture process,and can also appraise the optical system performance in optical alignment process rightly,which has very important meanings in advanced manufacturing field of space optical aspheric mirrors.

关 键 词：光学加工 光学检测 非球面反射镜 有效通光口径 非线性误差校正 空间光学相机 

分 类 号：TH706[机械工程—仪器科学与技术]