Phase-shifting interferometry method and system

摘要

An interferometry method including: i) forming an optical interference image by combining different portions of an optical wave front reflected from multiple surfaces; ii) recording an interference signal at different locations of the optical interference image in response to varying a property of the optical wave front that causes pairs of the multiple surfaces that have different optical path separations to contribute differently to the interference signal; iii) transforming the interference signal for at least one of the locations to produce a spectrum having a peak at a spectral coordinate corresponding to each pair of the multiple surfaces; and iv) identifying the spectral coordinate of the peak corresponding to a selected pair of the multiple surfaces.