Spectral analysis algorithm of vibration effect in phase-shifting interferometry

In the phase-shifting interferometry, the surface phase diagram is corrected by spectral analysis of the 'intensity-phase pattern' (the relationship between the interference intensity and the measured phase) of each phase-shifting image to achieve the purpose of reducing the vibration effect. This spectrum analysis algorithm is different from the previous methods. It does not determine the phase diagram, but corrects the phase diagram obtained by PSI measurement. It has few restrictions on the surface shape, and unlike the spatial Fourier method, it does not require high-density spatial carrier fringes, although at least a fringe of phase departure is recommended. The error between the influence of the simulated vibration signal on the phase and the influence of the actual measurement signal on the phase is less than 5 %.