The working principle of profilometry varies depending on the type:
- Contact Profilometry: A stylus is dragged across the surface, and its vertical displacement is measured to create a surface profile. - Non-Contact Profilometry: Techniques like laser triangulation or interferometry are used. For instance, in white light interferometry, light is split into two beams that reflect off the surface and a reference mirror. The interference pattern is analyzed to determine surface characteristics. - AFM: A cantilever with a sharp tip scans the surface. The deflection of the cantilever is measured using a laser beam and photodetector setup, providing a high-resolution topographic map.
