title: Video-rate fringe analyzer based on phase-shifting electronic moiré patterns.
abstract: We have developed a fringe analyzer that delivers the phase distribution at a video rate from a fringe pattern containing a spatial carrier. It is based on parallel generations of three phase-shifted moiré patterns through electronic multiplication with computer-generated reference gratings and low-pass filtering. The phase distribution is derived by the subsequent parallel processing of these patterns on the basis of a three-step phase-shifting algorithm. By modification of the bias phase distribution of the reference gratings, several functions, such as correction of an initial wave-front error, are realized in real time. The usefulness of this analyzer is demonstrated experimentally for phase measurements by grating-projection surface topography and interferometry.
authors.forename: J
authors.initials: J
authors.lastname: Kato
authors.forename: I
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Kuwashima