Software System For Simultaneous Phase-shifting Interference

It is great significance for surface quality evaluation,functional characteristics analysis and functional quality assurance to measure the dynamic surface topography and structure.In this paper,focusing on the requirements of dynamic surface topography and structural precision measurement and combining with the non-contact and high-precision characteristics of optical interference technology,the simultaneous phase-shifting surface microscopic interferometry of prism spectroscopic is implemented.Mainly,some problems that several errors were caused by prism spectroscopic are studied.And some algorithm is proposed to solve those problems and build a measurement software system.For the registration problem of simultaneous phase-shifting interference patterns,a new method based on SURF and RANSAC is proposed.Through the registration of background image with certain characteristics,the transformation relation between the images is obtained,which is used to the phase-shifting interference patterns to realize the position registration.It not only is effective on the translation but also rotation caused by the optical path.And the influence of measurement accuracy,which due to the position misalignment caused by spectroscopic interference,is effectively suppressed.Aiming at the problem of unequal intensity of interference,the intensity correction algorithm based on the interference equation is proposed,which is realized by the reference spot and measuring spot intensity ratio coefficient.The algorithm can effectively eliminate the ripple error of phase recovery.For the acceleration of simultaneous phase-shifting interference dynamic surface measurement,the implementation of image transform algorithm and morphology reconstruction algorithm is put forward based on CUDA.Through the experimental test of the speed-up ratio and the precision,the effectiveness and practicability of the parallel algorithm are verified.Combining simultaneous phase-shifting microscopic interference with dynamic surface measurement of the optical hardware system,an instrument software system based on Visual Studio 2013 platform has been developed.And the reliability and accuracy of the system is verified by the test of measurement system.