White light interferometry for fast areal surface measurement based on GPGPU

White-light interferometry is always an extremely useful and powerful tool for optical surface measurement. In this paper, a novelty method based on rapid positioning and fast surface measurement is proposed. The adjustment of optical path difference (OPD) is done automatically by a wavelength scanning method, and the processing of white-light interference patterns is accelerated by GPGPU which stands for General-Purpose computation on Graphics Processing Units, also known as GPU Computing. Graphics Processing Units are high-performance many-core processors in which the data are processed in parallel. As a result, the time we need to obtain a surface shape is reduced to ten percents compared with the conventional white-light interferometry. With these advantages, it is possible to measure a rough and areal surface in a short time.