An Qichang, Zhang Hanfu, Wang Kun, Liu Xinyue, Li Hongwen
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Jilin Provincial Key Laboratory of Intelligent Wavefront Sensing and Control, Changchun 130033, China.
Sensors (Basel). 2023 Jul 25;23(15):6650. doi: 10.3390/s23156650.
To improve their spatial resolution and detection capabilities, future ground-based optical telescopes will have a size of 30 m, and the aperture of space telescopes will be increased to 10 m. Such large optical systems necessitate the development of large integrated testing equipment. In this study, spectrum and system alignment measurements and wavefront quality checking were performed using the sub-aperture detection method and a fiber-connected Photonics Scanning Pentaprism (PSP). First, the system was aligned using an optical truss, ensuring that the optical axis was properly positioned. Second, using a sub-aperture light beam though the entrance pupil, light spots were formed on the focal plane and transmitted to the spectrometer via fibers to obtain the corresponding spectral components. Then, by taking measurements at different system positions, a full-aperture spectrum response could be reached. Lastly, by photon-integrated interference on the focal plane, intensity interference fringes could be projected at the entrance pupil of the system. And the wavefront quality of the system could be verified by observing the fringe deformation. The measurement accuracy of the optical axis of the system is better than 2 mrad. The spectral measurement accuracy was better than 5%, and the wavefront measurement accuracy surpassed 0.1 wavelengths (1 wavelength = 633 nm). This study effectively enhanced the detection and in situ calibration capabilities of large telescope systems, ensuring that the performance requirements can be met in the design of future telescopes.
为了提高其空间分辨率和探测能力，未来的地基光学望远镜口径将达到30米，而太空望远镜的口径将增加到10米。如此大型的光学系统需要开发大型综合测试设备。在本研究中，使用子孔径检测方法和光纤连接的光子扫描五角棱镜（PSP）进行了光谱和系统对准测量以及波前质量检查。首先，使用光学桁架对系统进行对准，确保光轴定位正确。其次，通过子孔径光束穿过入射光瞳，在焦平面上形成光斑，并通过光纤传输到光谱仪以获得相应的光谱成分。然后，通过在系统的不同位置进行测量，可以得到全孔径光谱响应。最后，通过在焦平面上进行光子积分干涉，在系统的入射光瞳处投射强度干涉条纹。通过观察条纹变形可以验证系统的波前质量。系统光轴的测量精度优于2毫弧度。光谱测量精度优于5%，波前测量精度超过0.1个波长（1个波长 = 633纳米）。本研究有效提高了大型望远镜系统的探测和原位校准能力，确保在未来望远镜设计中能够满足性能要求。
