A method to measurement of optical axis eccentricity and fitting about the aspheric mirror with the high-precision three-coordinate measuring machine(CMM) is presented. By establishing 2d/3d measurement coordinate system, The axis of fitting of the cylinder is selected according to the machining and assembly reference of aspheric mirror, Generating a number of concentric circles automatic measurement strategies, And make the points on each equal circumference, The probe head of the CMM is sampled on the surface of the measured aspheric mirror according to the measured strategy path to obtain the point coordinates of the distance of the reference axis, the measured surface is fitted to obtain the eccentricity of the aspheric mirror optical axis. Hyperboloid concave mirror to make use of the proposed method in the practical testing, the results show the actual processing of eccentricity is 0.0190mm, the standard deviation of 3.6×10-4mm, to meet the requirements of the design of eccentricity is less than or equal to 0.02mm.And testing the high precision centering lathe cutting machine frame fixed axis aspheric reflector components, the data indicators meet the requirements of assembly process. The accuracy of this method is high, and the traditional measuring method is easy to be affected by the precision of the tooling and easy to scratch the mirror. With large work surface, large caliber, back light weight loss (special-shaped structure) of aspheric mirrors optical axis eccentricity detection, not only suitable for different aperture aspheric mirrors the processing quality of qualified determination, but also in the machining, high precision of aspheric mirrors system with adjustable guiding role and effectively promote R-C spherical reflector optical system assembly accuracy and efficiency.
The paper presents a method based on the principle of auto-collimating to assemble the large-aperture laser beam reduction system. The method solves the problem of using fiber laser, plane mirror and Hartman wavefront sensor to realize the precision assembling of the large-aperture laser beam reduction system in the absence of large-diameter standard light source. Using the method, The large-aperture laser beam reduction system is successfully assembled in the big science project. And the technical index of the system is tested and the uncertainty is analyzed. The near field modulation degree is 1.03, the contrast is 0.025, the wavefront distortion is 0.476λ(λ=1053nm), and the system meets the requirements of the engineering index.