New phase measurement profilometry by grating projection

Abstract

Time phase shift is an effective, reliable, and commonly used technique to measure the phase of fringe patterns. The major disadvantage of this technique is that it involves phase-shift devices, which introduce errors during the process of phase shift and require high compatibility of the photoelectrical performance of different detectors used in the experiment. More importantly, since at least three fringe patterns are needed to reconstruct the 3-D surface of the object, this technique is inappropriate for use under dynamic conditions. We propose and demonstrate a novel technique, i.e., grating projection tricolor fringe profilometry, for rapid determination of the profiles of objects. The technique, which is based on only one fringe pattern, obviates the need of phase-shift devices. Thus, errors resulting from the process of phase shift can be eliminated and rapid measurement can be achieved.