Wei Haisong, Hu Haixiang, Yan Feng, Chen Xindong, Cheng Qiang, Xue Donglin, Zhang Xuejun
Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin, 130033, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Rep. 2018 May 8;8(1):7272. doi: 10.1038/s41598-018-25632-0.
To test large-aperture space optical systems in a simple and highly efficient manner, the scanning Hartmann test (SHT) has been used to measure the sub-aperture wavefront slopes of optical systems by scanning with a collimated beam followed by retrieval of the overall wavefront form. However, the use of such a method contains a crucial flaw in that pointing errors of the translation stage can severely affect the test accuracy. Therefore, a multi-beam stitching method is proposed to correct pointing errors by stitching together data obtained by successive sub-aperture acquisition. In this paper, a test principle and a data processing method are detailed. Simulation results theoretically verify a high precision for the stitching algorithm. Furthermore, a multi-beam array stitching test system (MASTS) is developed and used to successfully test an actual space optical system of ∅800 mm. The MASTS shows a deviation of 1/50 λ (λ = 632.8 nm) root mean square (RMS) from the interferometric results and a repeatability of 1/80 λ RMS, which demonstrates high precision, high repeatability and low sensitivity to air turbulence compared to interferometric measurement. In future engineering applications, the MASTS has great potential to solve the test problems of space optical systems using ultra-large apertures.
为了以简单高效的方式测试大口径空间光学系统，扫描哈特曼测试（SHT）已被用于通过准直光束扫描测量光学系统的子孔径波前斜率，随后恢复整体波前形状。然而，使用这种方法存在一个关键缺陷，即平移台的指向误差会严重影响测试精度。因此，提出了一种多光束拼接方法，通过将连续子孔径采集获得的数据拼接在一起，来校正指向误差。本文详细阐述了测试原理和数据处理方法。仿真结果从理论上验证了拼接算法的高精度。此外，还开发了一种多光束阵列拼接测试系统（MASTS），并成功用于测试一个直径为800 mm的实际空间光学系统。MASTS与干涉测量结果相比，均方根（RMS）偏差为1/50 λ（λ = 632.8 nm），重复性为1/80 λ RMS，这表明与干涉测量相比，它具有高精度、高重复性和对空气湍流低敏感性的特点。在未来的工程应用中，MASTS在解决使用超大口径的空间光学系统的测试问题方面具有巨大潜力。
