Optics and Precision Engineering, Volume. 33, Issue 6, 895(2025)
Performance simulation and wavefront measurement of telescope at cryogenic temperature
Cryogenic space telescope is applied in 90K cryogenic environment, but developed in a laboratory environment at room temperature and pressure. The huge differences in application and development environments result in two different sets of parameters of optical components. A telescope with good image quality at cryogenic temperature is actually a system with large aberration in laboratory environment. In order to quantitatively evaluate the imaging quality of a cryogenic telescope, a structural thermos optical performance simulation was conducted,and a testing method for wavefront error of the telescope in a 90 K cryogenic environment was designed. Firstly, the working temperature of the telescope at 90 K is achieved through the dual cooling of liquid nitrogen cold shroud radiation and refrigeration machine in the vacuum chamber. The wavefront measurement of the telescope is achieved through the interference measurement of parallel light tube beam expansion. Secondly, the error sources of the testing system were analyzed and calibrated to correct the test results. Finally, the consistency between the measured cryogenic wavefront values and the model simulation of the telescope was compared and analyzed, as well as the manifestation of wavefront errors and the corresponding mapping relationship of structural design. The experimental results show that the design simulation of the telescope is accurate, the 90 K low-temperature wavefront testing method is reasonable and feasible, the simulation accuracy is better than 20 nm,and the wavefront testing accuracy is better than 9 nm. The test results can be used for the design improvement of the optical mechanical system of the space telescope.
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Junru SONG, Weiming TONG, Zhongrui JIN, Dongke HE, Zhiyuan LIU, Yue MA. Performance simulation and wavefront measurement of telescope at cryogenic temperature[J]. Optics and Precision Engineering, 2025, 33(6): 895
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Received: Oct. 8, 2024
Accepted: --
Published Online: Jun. 16, 2025
The Author Email: Junru SONG (sjr1987bit@163.com)