Research of high-precision stitching workstation for large-aperture asphere

With the wide application of large convex asphere, modern optics has also put forward higher requirements for its measurement. Aiming at the problems of serious deformation by mounted, low measurement accuracy and dynamic range, and low measurement efficiency in the current optical measurement, this paper has researched high-precision stitching workstation for large asphere. The workstation adopts a vertical measuring structure. The optical axis of the test surface and interferometer are both vertical, which is advantageous for mounting the test surface and reducing the deformation. For adjustment of test surface, a four-axis platform is designed which can precisely adjust translation, tilt and rotation. At the same time, a adjustable stage which can replace CGH is designed. After the CGH and the test surface are accurately aligned through the five-axis adjustable stage, the aberration of off-axis subaperture can be fully compensated. The null scan test of full aperture can be achieved. The measurement accuracy of subaperture stitching is greatly improved. The vibration isolation system is designed to reduce the influence of vibration on stitching. Finally. The finite element analysis and kinematics model of the key components of the stitching workstation are carried out to verify the rationality of structural design.