Off-axis optical system has become the main direction in the development and application of modern optical technology, which boasts such merits as large aperture, wide viewing field and long-focus. The large aperture engineered off-axis optical product is required the capabilities of high stability and environmental adaptability, which causes bigger challenge to the installation and adjustment technology.
After two years’ dedicated research, a set of installation and adjustment platform of spatial off-axis optical system has been designed and established in the thousand level laboratory of Xi’an Institute of Optics and Precision Mechanics under the leadership of Li Hua, director of System Engineering Department, with Zhang Xuemin, Song Xing, etc. as the assembling backbones and Duan Jiayou as technology consultant, and the installation and adjustment technology has been testified. The platform is based on the principles of photoelectric auto-collimation and spatial intersection measurement to realize the high-precision initial positioning of off-axis optical components, and the platform applies laser interference auto-collimation measurement method and computer-aided installation and adjustment technology to achieve the precise adjustment of system wave-front aberration. After the theoretical analysis to the offset wave aberration of off-axis optical system, the auxiliary installation and adjustment mathematical model has been simplified, specifications have been quantified and the accuracy and efficiency of assembly have been improved.
In September 2015, the engineering product of off-axis three reflection focusable optical system was installed and adjusted. After striving for two consecutive months among difficulties, young assemblers including Song Xing and Zhang Xuemin successively completed the micro-stress assembly of large aperture primary mirror, precise location and adjustment of secondary mirror, precise spatial installation of focusing platform and precise measurement of system coaxial degree, and the testing indexes of system wave aberration are better than designed one at different imaging locations. It has won the high praise from users and the technical staff.
The successful installation and adjustment of the large aperture engineered off-axis optical product stated above and the actual verification to the assembly technology show that our institute has conquered the difficulty of off-axis assembly technology and mastered the installation and adjustment technology of large aperture off-axis optical system. Therefore, computer-aided integration technology was improved and successfully applied, technology backbones were cultivated and the research, manufacture, integration capability of optical engineering products in our institute were advanced.