Phase- and tilt-shift determinations by analysis of spectra sidebands for phase-shift interferometers

摘要

A spatial frequency domain method is presented to deal with tilt-shift errors and random phase shift in temporal phase-shift interferometry. The proposed method determines tilt shift and phase shift by analyzing positions and phase variances of sidebands in spatial frequency domain. The method is computationally fast for it is noniterative and needs only one 2D Fourier transform for each spatial carrier interferogram. No initial estimations are required and no ambiguous results are generated with the proposed method. Simulations indicate that the proposed method could detect tilt shift and piston phase shift with high accuracy. Results of experiments conducted in the presence of vibration demonstrate that the proposed method could alleviate fluctuations in the retrieved phase map. The method could be applied to interferometers that are uncalibrated or with an unbalanced piezoelectric transducer, besides interferometers in unsteady conditions.