Development Memoir Of Aspheric Surfaces

This thesis includes two kinds of ashperic fabrications: Fabrication of a small f-number RC astronomical optical system;Fabrication of a grazing incidence telescope's objective made of Zerodur.In the first chapter, the demands of aspheric surfaces in the world were introduced. The importance of optical systems using aspheres and the trend of optical systems were introduced. The research background of this thesis and the techniques of aspheric fabrication in the world were introduced.In the second chapter, a CNC aspheric grinding machine with novel operational principles has been manufactured and the novel operational principles have been proved to be correct by experiments. The novel CNC aspheric grinding machine has a precision capability of 5μm for optical components as large as 600 across. A concave hyperboloid with f/1.2 is the primary mirror of a RC astronomical optical system, which maximal aspheric departure is about 0.214mm and the diameter is 350mm, has been fabricated by our novel CNC aspheric grinding machine with the residual error of PV=4.31μm. A RC astronomical optical system with small f-number was fabricated which aperture isФ350mm and the focal length is 1400mm. The relationship between S.D. and the system's RMS has been proved to be correct by analyzing the system error datum. In the summary of this chapter, the advantages and problems of the novel CNC grinding machine were summarized.In the third chapter, the applied background of X-ray telescope (XRT) was introduced. Wolter-type is adopted internationally as a XRT. And the structure of Wolter-type XRT is briefly introduced. The manufacture difficulty of incorporated and separated WolterⅠXRT ware discussed. And the incorporated WolterⅠXRT was chosen to be fabricated. The grinding and polishing techniques of grazing-incidence XRT were discussed. The diffractions of thin-ring telescope were discussed. The whole grinding of grazing-incidence XRT includes two procedures as incorporated grinding and separated grinding. Different test methods of separated grinding were discussed. The WolterⅠtype grazing incidence XRT had been fabricated firstly in China which material is bare Zerodur. The axial resolution of the XRT is 2.7 arc-seconds in visible wave band. The RMS roughness (Ra) of two reflective surfaces is 0.473nm. The Foucault test method was firstly used in the built procedure. This test method is different from the generally methods in other counties. In the summary of this chapter, the experience and defaults were summarized during the built procedure. And the improvements during the grinding and polishing were discussed briefly.In the forth chapter, the research contents of this thesis were summarized. And the innovations and the significance of this thesis were summarized.