Speckle patterns of weak diffusers: effect of spherical aberration

The structure and dynamics of speckles formed by a weak diffuser in the presence of severe spherical aberration have been studied. Two cases were considered. In the first case the diffuser is treated as an object, and the speckles are observed in the paraxial, least confusion, and marginal planes. In the second case the diffuser placed in various planes is illuminated by a spherically aberrated wave front from a lens. The results are illustrated by photographs, and heuristic arguments are given to account for them.