Approaches in generalized phase shifting interferometry

A sample of phase-shifting algorithms suitable for accommodating arbitrary phase steps is passed in review. Although not exhaustive in nature, the paper describes a wide range of concepts which have been applied to generalized phase shifting interferometry. Linear phase shift miscalibrations and nonlinear sensitivity of the piezo electric device are known to introduce errors in phase measurement. The study reveals that of the various algorithms proposed most are suitable for compensating only one of these two error sources. Application of a direct search stochastic algorithm would appear to be a promising step towards characterizing the nonlinear response of the PZT.