Microscopic surface topography using a projection interference fringes interferometer with phase retrieval by digital analysis

Projection interference fringe interferograms have been analyzed with specialized digital image processing techniques to yield topological maps of microscopic surfaces. The theory of use of the projection interference fringes interferometer is presented. The set of image processing techniques used in the analysis, including specialized phase retrieval algorithms, are also described. Experimental results from a variety of metallic surfaces, a ceramic surface, and a transparent object are shown. Surface characterization statistics from these analyses are compared to statistics obtained using stylus profilometers.