Verification of phase measurement error sources in phase-shifting interferometry with four step phase-shifting algorithms.

The phase-shifting technique is one of the most important techniques in interferometry. The measurement accuracy of this technique is affected by several kinds of systematic and random errors like miscalibration, nonlinear response and tilt shift of the phase shifter, nonlinear recording, speckles, fringe fluctuation, etc. In this paper, a method for verification of all of these phase measurement error sources is proposed by introducing a grayscale image. This image is composed from the lattice-site representation determined by a four step phase-shifting algorithm, which represents the distribution of phase-shift angle values. The shape of the grayscale image is definitely more expressive and demonstrative for the kinds of measurement error sources than the black dot distribution in lattice-site representation. So, with this technique, we can recognize the existence of various measurement error sources and roughly estimate their magnitudes before proceeding with experiments. Our method is to be rather qualitative than quantitative. The availability of this method is discussed in a phase-shifting Fizeau interferometer and a fringe projection profilometry. This method is useful in all kinds of interferometric measurements based on the phase-shifting technique.