Device and method for measuring optical element surface shape in low temperature environment

Abstract

In order to solve the technical problem that the existing method for testing the surface shape of optical elements in a low temperature environment is limited by the caliber of the interferometer and the deformation of the vacuum container window glass will introduce test errors, the present invention provides an accurate, reliable and easy-to-operate low-temperature Device and method for measuring the surface shape of an optical element in an environment. The optical element surface shape measurement device includes a wavefront sensor, a collimator, and a vacuum container; the collimator is provided with a window glass, the vacuum container is provided with a temperature control cover, and the temperature control cover is provided with a liquid nitrogen heat sink; the temperature control cover Together with the liquid nitrogen heat sink, it provides the low-temperature environment required by the design for the optical element to be tested; the collimator is sealed and connected with the vacuum container to form a sealed cavity; the wavefront sensor is located outside the vacuum container, and its position is the same as the window on the collimator The glass corresponds; the wavefront sensor can both output the light beam and detect the light beam exiting the window glass. Compared with the traditional interferometric measurement method, the invention has strong anti-airflow and anti-vibration capabilities.

Description

technical field [0001] The invention belongs to the field of optical detection, and relates to a device and method for measuring the surface shape of an optical element in a low-temperature environment. Background technique [0002] Infrared optical systems are widely used in fields such as astronomical observation, earth observation, and weak target detection. Especially in the field of astronomical observation, due to the low temperature of stars and interstellar medium, the radiation is mainly light waves in the infrared band. The signal-to-noise ratio of the currently used infrared astronomical detector system is mainly limited by the background radiation, and the most important radiation comes from the radiation of the detector itself. In order to improve the signal-to-noise ratio of the system, it is very important to control the radiation of the detector itself. A feasible method is to reduce the temperature of the optical system itself to reduce its own background r...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the technical problem that the existing method for testing the surface shape of optical elements in a low temperature environment is limited by the caliber of the interferometer and the deformation of the vacuum container window glass will introduce test errors, the present invention provides an accurate, reliable and easy-to-operate low-temperature Apparatus and method for measuring surface shape of optical element in environment

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