The Research On The Testing Methods Of Large Aperture Aspheric Mirror

Optical systems with large aperture have been widely used in astronomical optics, space optics, space object detection and identification on the ground in decades. Large aperture aspheric mirror can expand field, simplify the system, increase spatial resolution and enhance signal energy, so it is a key technique for developing the optical systems with large aperture. The testing technology is the restriction when we manufacture the aspheric mirror, so it must be overcome for using in optical systems. Therefore, the research on the methods for the test of large aperture aspheric mirror has great meaning in the astronomical observation, space remote sensing and early warning field.This paper researches on the testing methods of large aperture aspheric mirror and gives the methods for a reflected aspheric mirror whose aperture is 4m, relative aperture is 1:1.5 and testing shape accuracy isλ/10 for PV. For the indexes of this aspheric mirror, the test can not been completed by using traditional method. It presents an austere challenge for manufacturing and testing technology. It is necessary to use advanced technology and equipments. The progress of the testing conditions and methods is certain requirement to finish the test.This dissertation, which researches on the testing method for the aspheric mirror with concrete indexes, includes four aspects, making the testing program, designing the optical system for the testing system, analyzing the accuracy of the testing system and testing the aberrations of the compensator.The feasibility and practicability of the testing methods are considered to choose the compensation method combined the ZYGO interferometer. Then, we give two testing methods and design results for the mirror, which are Offner compensation method and three-piece compensation method. For the application of the design, the precision analysis must be made. In this paper, we set down the tolerance of fabrication, measurement and alignment, and analyze the accuracy of testing system. For the compensator, testing the aberration is an important technique for using compensator. We discuss the testing method using computer generated hologram to test the compensator aberration and simulate the hologram.In this paper, the research and design of the testing method for the m-grade aspheric mirror is a key step in testing the large aperture aspheric mirror to make a breakthrough on technology and instruct the practice. Furthermore, this research offers good technique support for the fabrication of large aperture aspheric mirror in the future.