Theoretical analysis of Stoilov algorithm in phase shifting interferometry

Stoilov algorithm is a recently developed phase shifting algorithm for phase retrieving in optical interferometry whose phase step is arbitrary Because the property of the algorithm varies with the phase step, it is important to determine an optimum phase step in order to minimize the phase measurement errors A detailed error analysis is carried out to reveal the relationships between the phase measurement errors and the phase step, according to which a suitable phase step can be selected A phase step of 52° will minimize the influence of the 2nd order phase shift error while 90° is more effective for systematic and random intensity errors A comparison of Stoilov algorithm and Carre algorithm shows that the former is much better As for Hariharan algorithm, which is a special case of Stoilov algorithm, is recommended to use when the phase shift can be accurately calibrated, otherwise Stoilov can be selected with the phase step around 90°