摘要
为了减小瑞奇-康芒法中瑞奇角测量误差,提升对大口径平面镜面形的检测精度,提出了一种基于激光跟踪仪的瑞奇角在位检测方法。首先使用激光干涉仪与靶球构建离焦定位光路,根据检测结果中Zernike power项系数精确地定位干涉仪焦点的空间坐标;随后用激光跟踪仪的靶球对待测平面镜的镜面及外轮廓进行特征点采样,并由采样点拟合出待测平面镜及瑞奇-康芒检测光路完备的空间几何模型,通过在位计算得到瑞奇角。通过数值仿真,分析出运用该方法检测瑞奇角的相对误差不超过0.017%;相比传统利用平面镜光瞳面的图像压缩比计算瑞奇角的方法,本文方法将瑞奇角的测量误差从约0.2°减小到了0.005°以内。在对430 mm平面镜瑞奇-康芒的检测实验中,选择2个角度进行测量,得到瑞奇角的大小为39.18°和21.12°。解算面形后,得到的平面镜Zernike power项系数的复原误差从6.31%降低至0.028%。通过该方法能够更加精确地测量瑞奇-康芒法中的瑞奇角,从而提高了瑞奇-康芒法对平面镜面形的检测精度。
Objective High-precision large optical flats are indispensable in astronomical optics and space optics.For example,large optical flats can be used as standard inspection mirrors for large-aperture optical systems to achieve system calibration or as standard sub-aperture mirrors to splice and test larger-diameter flat mirrors.Therefore,it is of great significance to detect the surface shape of large optical flats accurately.Ritchey-Common test is a special oblique incidence interferometry.The Ritchey-Common test optical path only needs to be built with a well-polished concave spherical mirror,so it is easy to implement in the optical detection workshop.The beam emitted by the interferometer is obliquely incident on the test flat,and the angle between the main optical axis and the normal of the test flat is called the Ritchey angle and is denoted asθ.The Ritchey angle is a critical parameter in the Ritchey-Common test.At present,there are two main methods for measuring the Ritchey angle:1)measuring the distance between the focal points of the system,the intersection point of the optical axis and the test flat,and the intersection point of the optical axis and the stand spherical mirror,and then calculating the Ritchey angle by the cosine formula;2)using the edge detection method to analyze the ratio of the long and short axes of the wave aberration image to obtain the Ritchey angle.However,in practice,it is quite difficult to accurately measure the distance between three points with the traditional ranging method,and the measurement process is easily disturbed by human subjective factors.In addition,the edge detection algorithm has low sharpness of the edge area of the interferogram,which brings difficulties to accurate identification.Therefore,it is also difficult to obtain an accurate Ritchey angle.An inaccurate Ritchey angle leads to inaccurate detection of the flat.The measurement of the Ritchey angle is essentially a geometric angle calculation.Meanwhile,the laser tracker has a very outstanding advantage in t
作者
曾昶宇
李金鹏
王鑫蕊
Zeng Changyu;Li Jinpeng;Wang Xinrui(CAS Nanjing Astronomical Instruments Research Center,Nanjing 210042,Jiangsu,China;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,Anhui,China;Nanjing Astronomical Instruments Co.,Ltd.,Chinese Academy of Sciences,Nanjing 210042,Jiangsu,China;Anhui Institute of Optics and Fine Mechanics,HFIPS,Chinese Academy of Sciences,Hefei 230031,Anhui,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2024年第12期233-243,共11页
Acta Optica Sinica
关键词
光学检测
瑞奇-康芒检测
瑞奇角在位检测
激光跟踪仪
optical detection
Ritchey-Common detection
Ritchey angle in-situ detection
laser tracker
