Fabrication and measurement of microlenses

Testing the shape of surfaces (spherical, cylindrical or aspherical) of optical elements by interferometric methods is one of the main subjects of quality control in optical industry. Out of the classes of interferometric methods, the two-beam interferometers with phase-conjugating mirrors (PCM's) are the most modern ones. The paper describes Twyman-Green- and Fizeau-interferometers using a self-pumped phase conjugating mirror a BaTiO3-crystal for testing optical components as ci,“,„ „I,Lerical and cylindrical as well as aspherical optical surfaces. We especially discuss the problem of applying an appropriate phase shifting mechanism in an interferometer with a SPPCM.