AUTOCORRELATION FUNCTION FOR MULTIPLY SCATTERED-LIGHT

A simple theory for the autocorrelation function for multiply scattered light from isotropic, independent particles with a size small compared to the wavelength of light is described. It assumes that multiple scattering is a Poisson process (with an average number of scattering eventsm) and that the correlation function for light successively scattered through the anglesθ1, θ2, ..., θn, observed at angle θ with respect to the incident beam, is given by a product of the single scattering correlation functions. A Monte-Carlo method was used to obtain the correlation functionCm (θ, t). The results show that the reduced radius decrease withm and θ. The second cumulant for the homodyne case saturates at a value of 0.40. These predictions are in good agreement with those found experimentally. © 1991 Academic Press, Inc. All rights reserved.