Canceling the momentum in a phase-shifting algorithm to eliminate spatially uniform errors

摘要

In phase-shifting interferometry, phase modulation nonlinearity causes both spatially uniform and nonuniform errors in the measured phase. Conventional linear-detuning error-compensating algorithms only eliminate the spatially variable error component. The uniform error is proportional to the inertial momentum of the data-sampling weight of a phase-shifting algorithm. This paper proposes a design approach to cancel the momentum by using characteristic polynomials in the Z-transform space and shows that an arbitrary M-frame algorithm can be modified to a new (M + 2)-frame algorithm that acquires new symmetry to eliminate the uniform error. (C) 2016 Optical Society of America