An automatic focusing module for White light scanning interferometer

摘要

An automatic focusing module is developed in this study using Mirau's interferometer, beam splitters, CCD camera and a computer. The module can automatically adjust the focus position depending on how far it was initially. The surface profile and the heights between 30 different time for a standard specimen are measured using the developed system. The repeatability of the results shows that the module can detect the focus position within ten seconds and allow rapid acquisition of surface profile. Besides rapid detection of focus position automatically, low cost of the system components is also an added advantage of using this technique in comparison to other techniques.