Study of laser speckles in the presence of spherical aberration

It has been observed that in case of an imaging geometry, the speckle size and shape depend upon the aberrations, provided the scattering spot size is smaller than the point-spread function of the optical system. In the presence of spherical aberration the speckle pattern becomes radially streaky. Photographs of the patterns at paraxial, marginal, least-confusion, and defocused planes are given. When the diffuser is given a translatory motion the speckle at a point in the observation plane moves along the shadow of a knife edge (with its edge parallel to the direction of translation) placed at a suitable position in the pupil plane. Experiments with the atropinized eye also yielded the same results. A heuristic explanation for these results is included.