title: Fourier analysis of two-stage phase-shifting algorithms.
abstract: Differential phase-shifting algorithms (DPSAs) and sum phase-shifting algorithms (SPSAs) recover directly the phase difference and the phase sum, respectively, encoded in two patterns. These algorithms can be obtained, for instance, by an appropriate combination of phase-shifting algorithms (PSAs), which makes unnecessary the previous calculation and subtraction or addition of each individual optical phase by means of conventional PSAs. A filtering process in the frequency domain is presented that allows us to obtain in a simple and elegant manner a qualitative characterization with a Fourier description of the two-stage phase-shifting evaluation that reveals possible phase shifter miscalibration errors and unexpected harmonics in the signal.
authors.affiliation: Applied Physics Department, University of Vigo, Campus Universitario, 36310 Vigo, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Miranda
authors.forename: Benito V
authors.initials: BV
authors.lastname: Dorrío