Accurate Phase Analysis of Fringe Patterns by Spatiotemporal Phase-shifting Method

Abstract

Accurate phase analysis of waveform as fringe patterns is essential for a wide range of scientific and engineering disciplines. The phase-shifting method is a powerful tool to analyze the phase information of fringe patterns. This paper presents the fundamental principle and applications of a newly developed spatiotemporal phase-shifting method (ST-PSM) for noncontact three-dimensional shape and laser interference measurement. Simulation results indicated that ST-PSM had strong tolerance to random noise and a self-neutralizing function to eliminate the periodical phase error due to the nonlinearity of detector, intensity saturation, vibration or phase-shifting error, and the fluctuation of amplitude intensities due to the instability of laser source in the phase-shifting interferometry. The effectiveness was demonstrated experimentally from a non-contact shape measurement in fringe projection profilometry under extreme underexposure recording conditions. Furthermore, the ST-PSM realizes a much more stable measurement of phase and phase gradient distributions than the PSM in a Michelson laser interferometer experiment. We believe this technique has a significant impact on a variety of research and scientific fields.