Analysis, by the Monte Carlo method, of the validity of the diffusion approximation in a study of dynamic multiple scattering of light in randomly inhomogeneous media

A numerical simulation is reported of dynamic multiple (isotropic and anisotropic) scattering of light in a randomly inhomogeneous medium representing a suspension of light-scattering Brownian particles. The results of a simulation of the temporal autocorrelation function of backscattered light are compared with calculations carried out within the framework of the diffusion approximation for the radiation transport equation. It is shown that, although the diffusion approximation describes incorrectly low-order scattering, it is quite acceptable for dealing with high-order scattering.