FRACTALITY OF SPECKLE INTENSITY FLUCTUATIONS

Coherent-light diffraction on random phase screens with fractal proper ties leads to the formation of speckle patterns with peculiarities in correlation characteristics in the small-scale region. Such peculiarit ies are manifested in asymptotic behavior in intensity autocorrelation and structure functions in the vicinity of the zero values of their a rguments. Intensity fluctuations in the far and the near diffraction z ones are also characterized by values of fractal (Hausdorff-Besicovitc h) dimensions D-HB, differing from the corresponding Euclidean dimensi on. Relationships between the exponential factors of the structure fun ctions of boundary field phase and scattered-light intensity fluctuati ons as well as between values of D-HB have been obtained as a result o f speckle-formation analysis for different conditions. Their dependenc ies on the illumination and observation conditions obtained in experim ents with fractallike scatterers (rough glass plates) are in satisfact ory agreement with theoretical results. (C) 1996 Optical Society of Am erica