相移技术中五步等步长Stoilov算法的性能分析

Theoretical analysis of Stoilov algorithm in phase shifting interferometry

Stoilov算法是近几年提出的一种五步等步长相移算法。有关文献中的误差分析表明 ,该算法的性能优于四步等步长Carr啨算法闹懈隽耍樱簦铮椋欤铮鏊惴ǖ恼繁泶锸?,采用线性误差理论详细分析了算法的性能 ,尤其是算法性能对相移步长的依赖关系。分析表明 ,可以选择一个最佳的相移步长以有效减少位相测量误差 :相移步长为 5 2°时可有效抑制二次相移量误差的影响 ;相移步长为 90°时可极大地减少光强误差的影响。最后给出了Stoilov算法与Carr啨算法和Hariharan算法的比较。

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 Carré 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°