Research Of High-precision Aspherical Testing Technique Using Annular Sub-aperture Stitching Method

With the development of optical precision manufacturing technique, aspherical mirrors have been extensively applied in the optical systems. However, the limitation of the testing approaches has been one of the main obstacles for the developing of the application of aspherical mirrors. The annular sub-aperture stitching method proposed in this dissertation is an effective method for testing rotationally symmetric aspheric surfaces. This testing method does not use additional elements, e.g., CGH. As a result, the cumulative errors caused by the design, fabrication, and misalignments of this additional element will be removed, as well as the measurement cost will be greatly reduced.In this thesis, the basic knowledge about aspherics is illustrated. Then the principle of measurement of annular stitching technique and method of experiment are introduced. Third, the principle of the annular sub-aperture stitching algorithm is analyzed. Validity of algorithm is verified by simulation stitching, and sub-aperture overlap and calculating precision are analyzed through simulation modern for guiding practical experimentations better. At the end of the paper, a secondary parabolic with diameter108mm is tested by Zygo interferometer. Compared to the known results, the PV value of the experiment differs about1.89%and RMS value differs about1.09%. The stitched surface shape is similar to the known surface shape. This result shows that the stitching algorithm is practical.