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(1)　Fractal specklesOPTICS COMMUNICATIONS,156,pp.350-358,1998-11.

　Speckle patterns having fractal properties were generated experimentally by illuminating an ordinary diffuser with speckles produced in the Fraunhofer diffraction region of random fractal objects. The fractality of the speckle patterns manifested itself by the clustered appearance of intensities without any definite speckle size and was confirmed from a power law in intensity correlation functions. The size of the intensity clusters and the exponent of the power-law in correlation function were studied as a function of the fractal dimension of the first object. Despite the fractality of the speckles, the probability density of intensities was found to follow a negative exponential function. For comparison, three additional configurations using circular and ring-slit apertures were employed instead of the fractal objects. The properties of intensity correlations for these configurations were discussed on the basis of the properties of the illumination function over the diffuser, and the reason for the presence and absence of fractality in speckle patterns due to various optical conditions was elucidated.c 1998 Elsevier Science B.V. All rights reserved.