Generalized surface reconstruction and fringe analysis through phase measuring deflectometry

A deflectometry simulation system for measuring and generating the surface profiles of freeform optical elements was designed. Unlike alternative optical metrology methods, deflectometry systems utilize the principle of pixel to pixel point mapping to measure a specular optical surface. The in-lab set up uses readily available materials such as an LCD monitor, a CMOS camera, and other basic lab items such as optical posts and post holders. A software that enlists the usage of phase unwrapping in order to derive the incident and reflected light vectors from a surface under test. These vectors provide slope information which can then be integrated into a surface reconstruction. This allows for a non-contact surface reconstruction method as well as a simulation to help calculate the best respective placements of monitor, camera, and test surface. This type of system is useful in a measuring more challenging optical surfaces such as free forms and convex optical surfaces. Disclosures of the system and distance sensing lasers could enable a very user friendly and intuitive handler experience for creating the surface reconstruction profiles with much more reliable system geometry information and reduction of excess light and scattering noise. Multi rotation stages can also be used for adjusting tip and tilt angles of test surfaces.