Testing Big Curvature Surface Of Optical Element On Plane Interferometer With Spatial Carrier Heterodyne Interferometry

A kind of non-contact test method of optical surface with big curvature radius by using spatial carrier heterodyne interferometry on the plane interferometer is mainly studied in the dissertation. The measured surface error relative to the standard sphere appointed has been obtained by processing and analyzing the interference fringe formed on the plane interferometer, and the interference fringe of the measured surface tested with sphere interferometer has also been simulated. The method overcomes the disadvantages of contact test, and provides a suitable method particularly to optical surface with high precision and big curvature radius.The basic theory and method of testing big sphere surface with spatial carrier heterodyne interferometry is introduced in details in the dissertation. The hardware and software of the testing system has been designed and manufactured. Some pivotal techniques are emphasized specifically such as interference fringe processing, boundary extending, FFT phase distilling, phase unwrapping and Zernike polynomial fitting. A small plane interferometer is manufactured, and the software is designed with measured results showed in the form of data and figure. Furthermore, the interference fringe formed by the measured surface relative to the standard sphere is successfully simulated. Lastly, the experimental results of tested optical component is given and the error is analyzed on the base of experiments.