Photorefractive moire-like patterns for the multifringe projection method in Fourier transform profilometry

摘要

In the present paper, the method of simultaneous moire-like fringe pattern projection for Fourier transform profilometry is described. The photorefractive holographic interferometric process produces controlled moire-like patterns with two or more different variation directions. Each low spatial frequency fringe pattern is experimentally obtained as a result of the superposition of two high spatial frequency sinusoidal gratings, with slightly different pitches, for each fringe variation direction. These dynamic moire-like patterns are induced due to an optical holographic beating of the sinusoidal induced gratings in the volume of the photorefractive Bi12TiO20 (BTO) crystal sample used as dynamic holographic medium. Two or more moire-like fringe patterns, with at least two different variation directions, simultaneously (or not), are projected onto the object surface. Thus, this is the 2D fringe projection stage of our proposed Fourier transform procedure to determine the profile of a simple object. (C) 2016 Optical Society of America