Surface profilometry based on polarization analysis

We report a novel algorithm for the analysis of interferometric images for surface profiling. The algorithm can be used with any interferometric syste m in which the two interfering beams are orthogonally polarized. The algori thm is based on a measurement of the polarization state and gives a unique value for the path difference that is not subject to the ambiguities associ ated with fringe counting or phase unwrapping. A detector array allows the polarization state and hence the height of every pixel in the image to be d etermined simultaneously. The concept is easily extended to enable one to o btain the profiles of moving surfaces from a single pulse of illumination. (C) 1998 Optical Society of America.