Comprehensive Analysis Of Radial Shear Interference Errors

Radial shearing interferometry was widely used in aspheric surface detection because of its common optical path and no reference mirror.In order to explore the error analysis method of optical interferometer system and further improve the measurement accuracy,the main part of the radial shearing interferometer system for aspheric surface detection wass analyzed and processed in this paper,which improved the aspheric surface detection accuracy.The main contents of this paper are as follows:This paper described the principle and process of aspheric surface testing of radial shearing interferometry system,and introduced various methods of aspheric surface testing.The error analysis of the aspheric surface testing system based on radial shearing interferometry was carried out,focusing on the error analysis of the optical system and the image processing algorithm.In the optical system errors,based on the optical design software ZEMAX,the optical path of the radial shear interferometer system was ideally modeled,the error of processing parameters was modeled,and the attitude model of the system was modeled.The influence of processing parameters errors and setting errors on aspheric surface reconstruction was analyzed.Among them,component processing errors were quantitatively analyzed and extracted in system modeling;assembly errors;modeling and data analysis showed that aspheric attitude errors have a greater impact on aspheric surface reconstruction;and the impact of standard lens attitude errors on aspheric surface reconstruction can be ignored.In the image processing software MATLAB,the sources of algorithm errors were analyzed,including interferogram preprocessing algorithm,phase extraction algorithm,interference wavefront fitting algorithm,wavefront restoration algorithm,focusing on the optimization of phase extraction algorithm and wavefront fitting algorithm.Based on the systematic error theory of optoelectronic instruments,the errors of the radial shear interferometry system and its main links were comprehensively analyzed.The experimental system of radial shearing interferometry was built to collect fringes and compare them with high precision interferometer The test results obtained by the system after eliminating errors satisfy the requirements.The research method was feasible.