Abstract

In the late 1960’s, various investigators began to measure the diffusion coefficient of dilute suspensions of microparticles in various liquids using the autocorrelated signal of laser light scattered by the microparticles. By 1970, quite complete accounts of the experiments had appeared in the literature.¹ Early on, it was discovered that multiple scattering in more concentrated suspensions distorted the experimentally measured correlograms, thus strongly biasing the determination of the diffusion coefficient. Four different approaches were taken in order to address the multiple scattering problem. One group of investigators attempted to calculate^2,3 the effects of multiple scattering when only few multiple scatterings occurred. A second group of investigators attempted to simulate⁴ the effects of multiple scattering in the intermediate scattering regeime. A third group of investigators attempted to calculate for^5,6,7 the effects of multiple scattering in the diffusion limit. The forth group of investigators attempted to find scattering geometries in which multiple scattering is partially or totally suppressed.

© 1996 Optical Society of America