In order to measure the phase projection in moiré tomography, in this paper we
present a new spatial phase-shifting shearing interferometry that consists only
of a crossed grating and a linear grating. With it, six phase-shifted
interferograms can be acquired simultaneously. The intensity distributions of
these six interferograms are derived based on the scalar diffraction theory.
Analytical results indicate that phase shifts are symmetrically and consistently
distributed in the vertical and horizontal directions. Moreover, phase-shift
values depend primarily on the parameters of the optical structure. And a
six-step phase-shifting algorithm with arbitrary phase-shift values in two
perpendicular directions is proposed to extract the phase information. The phase
retrieval results of the spherical wave have verified the validity of the
proposed method. Finally, an experiment with a plane incident wave is performed
to measure the first-order derivative of the phase projection of a propane
© 2013 Optical Society of America
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