Three-dimensional static speckle fields. Part II. Experimental investigation

In Part I [J. Opt. Soc. Am. A 28, 1896 (2011) of this paper, the physical model for fully developed speckle is examined based on two critical assumptions. (i) It is assumed that in the object plane, the speckle field is delta correlated, and (ii) it is assumed that the speckle field in the observation plane can be described as a Gaussian random process. A satisfactory simulation technique, based on the assumption that spatial averaging can be used to replace ensemble averaging, is also presented. In this part a detailed experimental investigation of the three dimensional speckle properties is performed using spatial averaging. The results provide solid verification for the predictions presented in Part I. The results are not only of theoretical interest but have practical implications. Techniques for locating and aligning the optical system axis with the camera center, and for measuring out-of plane displacement, are demonstrated.