PHASE-MEASURING PROFILOMETRY USING SINUSOIDAL GRATING

When a sinusoidal amplitude grating is projected on an object, the surface-height distribution of the object is translated to a phase distribution of the deformed grating image. In this paper, two algorithms developed for phase acquisition of such images are presented and compared. The phase-acquisition algorithms are sufficiently simple that high-resolution phase maps using a high-resolution area detector array can be generated in a short time. The average detection error is within 30 mm, which can be reduced further by changing the period of the projected grating and the angle offset between the projection and the observation optics.