DEVELOPMENT OF A MICROSCOPIC LASER INTERFEROMETRY SYSTEM FOR PRECISION SURFACE MEASUREMENT

A new technique for the evaluation of precision surfaces using laser i nterferometry is presented. Laser interferometry creates a fringe patt ern which contains information about the surface texture of the specim en. The technique presented compares the ideal fringe pattern to the a ctual fringe pattern to determine the height deviation on the specimen . In this paper, a simulation model is used to predict the fringe patt ern for a given surface. The surface topography of a groove on a compu ter hard disk is then reconstructed from an experimentally obtained fr inge pattern. The reconstruction process is verified by comparing the reconstructed surface to a photograph of the actual surface.