Abstract: | The effects of an arbitrary small inclination between the two crossed gratings on moiré fringes in Talbot interferometry are discussed. The small inclination is formed by the rotation by a small angle gamma of the beam splitter's grating about the axis that is on the plane of the grating and has an arbitrary angle delta with respect to the lines of the grating. The results indicate that the small inclination has a great influence on measurements for which Talbot interferometry is applied, such as beam collimation and measurement of the focal length of a lens. The theoretical analyses are proved by experimental results. Some methods for judging the size of a small inclination are also proposed. |