Fourier analysis of two-run-times-two-frame phase shift algorithm

Two-run-times-two-frame phase shift method is reviewed and a new phase retrieval algorithm is proposed. The properties of two phase retrieval algorithms are discussed from the point of view of Fourier analysis. Analysis shows that the two algorithms are equivalently sensitive to phase-shifter miscalibration and irreproducibility, and the amplitude of phase error depends on the average phase-step error. The influences of the signal harmonics on phase measurement rely on the phase shift of the object beam. The effects of random noise on the two algorithms are generally different, but the same only when the phase step of the reference beam is equal to pi/2.