Influence of phase-shifting error of phase-shifting interferometry on the phase accuracy recovery

To study the influence of phase-shifting error on phase accuracy recovery, we can reconstruct the wavefront by controlling the phase-shifting error of a certain step in the actual measurement, and the surface information obtained is closer to the surface information of the real object. In this simulation investigation, there are two main methods to study the influence of phase-shifting error on phase recovery accuracy. One method is to add the same error to each step of the four-step phase-shifting, compare and analyze the obtained surface information with the test results without error through multiple simulation experiments, and obtain the research rules that the phase-shifting error in the first step and the third step, the second step, and the fourth step has the same influence on the phase accuracy recovery. Another method is to fix the phase-shifting error of the first step and the third step, change the phase-shifting error of the second step and the fourth step and analyze the result compare with the result without error through multiple simulation experiments. When there is an error in one step of the four-step phase-shifting, any error is added in the other three steps to make the fitting result closer to the result of the standard four-step phase-shifting.