Applications of interferometry for testing macro/microgeometry of optical surfaces

Abstract

New technologies to generate optical surfaces have been introduced recently. Interferometric testing of optical surfaces is widely used in laboratories but has only recently been applied in industry. Interferometric testing of plane, spherical and aspherical surfaces will be described together with the fringe analysis. Electronic phase measurement techniques eliminate photographing the fringe pattern for the analysis of the wavefront. Aspherical surfaces can be tested successfully by using computer generated holograms . Alternatively, aspheric surfaces in production can be tested with a master surface, using a holographic technique to be described. A slightly modified fringe analysis technique can be used for the study of the microgeometry of optical surfaces. For testing surfaces in the grinding stage two wavelength holography will be described.