The autocorrelation function of polychromatic laser speckle patterns near the image plane

• DOI: 10.1007/bf00620019
• Publication Date: 2004-11-26T04:00:34Z
• Authors: N. Nagamatsu; K. Nakagawa; T. Asakura; K. Morishita
• Keywords: 0103 physical sciences; 01 natural sciences

The autocorrelation function of polychromatic speckle patterns produced near the image plane of a double diffraction imaging system is experimentally studied. The condition under which the polychromatic speckle field obeys Gaussian statistics is further investigated as a function of the numberN of scattering cells, using the average contrast of the speckle intensity fluctuations. The profile of the autocorrelation function is next investigated as a function ofN and the defocused distance from the image plane. It is found that the average contrast and autocorrelation function of the polychromatic speckle intensity fluctuations converge less rapidly with an increase inN than those of the monochromatic ones.