Medium Wave Surface Calculation Of The Phase-shifting Interferometry And The Correction Of The Phase Shifter Technology

Phase shifting interferometry (PSI) has been widely used and accepted as a fast and accurate non-contact metrology tool. It is widely used to test optical element, optical system, and to detect optical surface and some physical parameter(such as temperature field, density field) related with optical path difference.In this thesis, the fundamental principle and characteristic for PSI are analyzed, some general error sources are discussed. A phase-unwrapping algorithm is designed and programmed, to unwrap the phase map derived from test data. A novel method for static interferogram analysis, named virtual grating moire fringe method that is integrated the conceptions of PSI and moire, is presented.Phase-shifter is the main component of phase shifting interferometer. Phase-shifting interferomtry usually suffers from systematic error caused by erroneous reference phase shift and nonlinear of phase-shifter. Based on the theory of least-squares estimation algorithm, the software is designed to calibrate linear and nonlinear errors of phase-shifter. A phenomenon named sub-processional motion which can induce the rotation of fringes in the processing of phase shift is analyzed, and the corresponding error to typical phase-shifting algorithm is investigated. In terms of error analysis, the criterions to control the error are presented.