Error behaviour in Differential Phase-Shifting Algorithms

摘要

Differential Phase-Shifting Algorithms (DPSAs) recover directly the phase difference encoded in two patterns being unnecessary the previous calculation and subtraction of each individual optical phase by means of well-known highly efficient and accurate Phase-Shifting Algorithms (PSAs). In spite of their interesting metrological applications, there are almost no published studies about the possible error-compensating methods in DPSAs, so it is necessary to investigate the tools to eliminate or minimize the inevitable effect of the principal errors on the measurement process. In previous works we have linearized and numerically simulated phase shifting errors and the presence of harmonics on the signal of several families of DPSAs obtaining analytical phase error expressions. In this paper we present an analysis of propagation errors for several DPSAs families considering, in a similar way than in PSAs, the frequency shifting property of the employed arctan function. A Fizeau phase-shifting interferometer is employed to verify the main characteristics of the analysed DPSAs families.