Correlation Properties of Light Backscattered Multiply from Fractal Aggregates of Particles Under Brownian Motion

Abstract

Studies on the phenomena of light scattered multiply from strongly absorbent media have been of benefit to metrology in biophysics, chemistry, and other areas. In this article, a temporal autocorrelation function of time-varying light backscattered multiply from a fractal aggregate of particles under Brownian motion suspended in an absorbent medium is investigated by means of Monte Carlo simulation. Temporal statistics of the backscattered light in time regions longer and shorter than the relaxation time depend on the fractal dimension and agree with the case of the homogeneously random media, respectively. The angular dependence of light backscattered multiply from fractal media varies dramatically depending on the fractal dimension in comparison with that from homogeneously random media. The influence of absorption generates the time shift in the temporal autocorrelation function in such a way that they vary approximately in accordance with a square root of the absorption coefficient but are independent of the fractal dimension, (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S1083-3668(99)00502-X].