INVESTIGATION OF COMMON-PATH INTERFERENCE PROFILOMETRY

The principle of laser common-path interference profilometry based on the theory of Gaussian beams is analyzed and its measurement equation is deduced, From the measurement equation, the main factors that affec t the vertical resolution of the profilometer are discussed, According to the conclusions of the analysis, laser common-path interference pr ofilometry can be used to measure microprofiles of fine surfaces with subnanometer vertical resolution. (C) 1997 Society of Photo-Optical In strumentation Engineers.