Large-diameter Telephoto Distance Axis Collimator And The Development Of Critical Optical Components

It has been 300 years of history since the aspheric surface was firstly used in the optical system, and the demand of high-powered aspheric surface is getting more and more huge. The aspheric surface optical parts have excellent optical performance, they could simplified optical system greatly. However, this kind of parts were not widely used right now because they were also hard to fabricated. As this reason, people were trying to solve this problem since Newton's time to today.Along with the development of space-technology, the large diameter, long-focal-length optical system is getting more and more important. The evaluation of imaging quality of this optical system is depend on large diameter, long-focal-length collimator. As this reason, the development of large diameter, long-focal-length collimator is imperative. Because the diameter is large and the focal length is long, this kind of collimator mostly uses reflective system, but usually this kind of system always has central obscuration. To avoid this situation, the off-axis parabolic mirror is the most easy way to use. Most of the space cameras use this kind of off-axis system.However, the fabrication of parabolic mirror is a problem, especially the increase of asphericity, diameter, off-axis quantity and surface figure. More than that, the large diameter, long focal-length, high precision off-axis parabolic mirror make this problem extremely difficult. This situation limits its application to a certain extent. As this reason, the report of large size off-axis parabolic mirror which is larger than 500mm in size is rarely seen.Nanjing astronomical instruments Co.,LTD would research and fabricate a set of optical parts which belong to a optical performance test system for a domestic research institute. This subject takes part in the task of the development of lm diameter off-axis parabolic mirror, comprehending the design of the whole system, the design scheme, processing technology, inspection scheme of the primary mirror, makes practical verification and final summarization.