Surface Roughness interferogram processing system

This paper introduces surface roughness interferogram processing system and how to use it to measure surface roughness by computer based image processing technology. The system can measure ra<0.2 um milti-gloove specimen and testing surface by processing a white light interferogram and measure H<5 um step height by processing a white interferogram and sodium light interferogram. former for the height measurement and later for CCD calibration with the advantages of absolute, non-contact, high-speed and automation.