A non-scanning, non-interferometric, three-dimensional (3D) optical profilometer based on geometric optics, critical angle principle, and the use of a charge-coupled device (CCD) camera is presented. The surface profile of the test specimen can be transferred into the reflectance profile. The reflectance profile, obtained from a CCD, is the ratio of the intensity at the critical angle to the intensity obtained at the total internal reflection angle. The optical profilometer provides a sub-micron measuring range with nanometer resolution and can be used to measure roughness or surface defects in real time.
© 2011 Chinese Optics LettersPDF Article