Two systems serve as examples of surface evaluation by means of laser scanners. One utilizes conventional image-processing methods in a hazardous environment. The other uses analysis of scattered light to extract the signature of the surface flaws. A general check list for optical design questions illustrates similarities and differences in the two applications.
Helen E. Gourley,
"Laser system for detection of surface irregularities", Proc. SPIE 0741, Design of Optical Systems Incorporating Low Power Lasers, (10 April 1987); doi: 10.1117/12.939746; https://doi.org/10.1117/12.939746