The effect of arbitrary small discrepancy between normal directions of grating planes in Talbot interferometry

The effect of nonparallel grating planes in Talbot interferometry is discussed when an arbitrary relative inclination exists between the normal directions of the two grating planes. The inclination can be composed of the two angles, and β, which are generated by rotating the beam splitter grating about the two axes parallel to and perpendicular to the line direction of the grating. Theoretical analyses indicate that the tilt angle of the moiré fringes is very sensitive to but not to β. Experimental results coincide well with the theoretical analyses. Methods of judging and removing the two small angles are briefly discussed.