Average Contrast of White-light Image Speckle Patterns

Abstract
An extensive experimental study on the average contrast of speckle patterns produced by white light at the image plane is reported in this paper. The speckle contrast is found to be determined by the complicated relationship between the spatial coherence of illuminating light, the point spread of an imaging system and the roughness properties of the objects. It is found that the previous results of Sprague, Parry and Pedersen on white-light speckle patterns are realized only when the object is spatially coherently illuminated and a large number of scattering cells are involved within the point spread of the imaging system.