A method of postprocessing the data from a phase-shifting interferometer is proposed that reduces the influence of vibration or other environmental disturbances occurring during the data-acquisition time. The method is based on spectral analysis of the time-varying intensity data from each of the camera pixels. A correction term is obtained at a frequency three times that of the phase-shifting device. No additional hardware is required, although the phase-shifting algorithm used must have phase steps of ≤π/3. Numerical studies have demonstrated reductions in the rms phase error of more than one and two orders of magnitude for vibration amplitudes of 0.1 and 0.01 rad, respectively, with a commonly used seven-frame algorithm. The influence of factors affecting the technique’s performance—in particular, miscalibration of the phase-shifting device, nonlinearity of the photodetector, and finite integration time—is also investigated.
© 1998 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.2650) Instrumentation, measurement, and metrology : Fringe analysis
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
J. M. Huntley, "Suppression of phase errors from vibration in phase-shifting interferometry," J. Opt. Soc. Am. A 15, 2233-2241 (1998)