The Research On The Processing And Testing Technology Of Special Cassegrain System

In recent decades, with the rapid development of science and technology, Cassegrain system is more widely used in space optics, astronomical optics, laser communications and other fields. The paper deeply researches the processing and testing technology of the aspheric surface in the Cassegrain system, whose focus is located between the primary mirror and the secondary mirror. In order to overcome the shortcomings of the traditional process, based on the processing indicators and the actual situation, after researching the CCOS technology and null test method, the paper improves processing and testing scheme, at the same time, analyzes the accuracy of the testing scheme.CCOS technology and traditional process is firstly combined in the process, at the same time, an independent testing technology of the secondary mirror is designed in accordance with third-order aberration theory, which ensures that the secondary mirror can be processed separately from the primary mirror. Because of the special focus location of the system, applying interferometer to conduct auto-collimation test can seriously block out the light, so the paper improves traditional technology, makes the PV value of the system reach λ/5with the help of knife-edge instrument.