Phase-shifting holographic moiré: phase-shifter error-insensitive algorithms for the extraction of the difference and sum of phases in holographic moiré.

Phase-steppingtechniques for the measurement of the difference and sum of phases in holographic-moiré-based interferometers are described. The phase-recovering algorithms for the extraction of this phase information is relatively insensitive to the inaccuracies of the phase-shifting device. This development promises not only to extend the domain of measurements but also to improve significantly the accuracy that can be achieved in deformation analysis and nondestructive testing of diffuse objects.