ULTRASTABLE ABSOLUTE-PHASE COMMON-PATH OPTICAL PROFILER BASED ON COMPUTER-GENERATED HOLOGRAPHY

A new scanning common-path interferometric profiler capable of absolut e-phase measurement is described. The key element is a computer-genera ted hologram, which acts as the beam-splitting element. Unlike most ab solute phase systems, it can be made entirely common path with respect to piston microphonics and is thus exceptionally stable. In addition to operating in scanning mode, the optical configuration permits simul taneous operation as a single-shot phase measuring interferometer and is thus capable of simultaneous form and texture measurements. The ope ration and stability of the scanning profiler are demonstrated experim entally. (C) 1998 Optical Society of America.