Statistical characteristics of spatial fluctuations in intensity of dispersed laser beams

Abstract

The statistical characteristics of spatial fluctuations of the intensity of dispersed laser beams are studied theoretically. The density of the probability distribution for the intensity is found and its transformation with a change in the longitudinal coordinate is studied. It is shown that a decrease in the intensity fluctuations and a drop in the contrast of the beam speckle structure occur with increasing distance from the initial plane in which the spatially inhomogeneous broadband field is assumed to be spatially coherent. A decrease in fluctuations is accompanied by an increase in the size of speckles in the direction of dispersion, as well as along the beam axis. An interpretation of the found regularities is given.