Regularized self-tuning phase demodulation for phase-shifting interferometry with arbitrary phase shifts

In this work, we develop a regularization technique to demodulate a phase-shifting interferogram sequence with arbitrary inter-frame phase shifts. With this method, we can recover the modulating phase and inter-frame phase shifts in the same process. As all phase-shifting algorithms, the assumption is that the wavefront under test does not change over time, but the introduction of phase-shifts can vary in a nonconstant way. A notable characteristic of this demodulation method is that not only can it recover the modulating phase, but it is also capable of filtering-out large amounts of corrupting noise. We will show numerical experimental results and comparisons with another already published method to see the performance of the demodulation technique developed herein.