Dependence of Transport Mean Free Path on Size of Scatterer

The transport mean free path l * characterizing the light diffusion phenomenon in highly dispersed media was theoretically predicted and compared with the values observed by the experiments of coherent backscattering. The Mie scattering theory for a spherical particle was used to calculate the scattering cross section, that leads to the l * of the suspension together with the number density of the particles. The anisotropy in a single scattering process was also taken into account. A series of experiments was made in polystyrene latex with 5% and 10% volume fractions and different diameters ranging from 0.1 µm to 3 µm. The experimental values of l * obtained from the coherent backscattering peak were in good agreement with the theoretical predictions. This study is performed to give a solid base to the coherent backscattering phenomenon as a new approach for material evaluation of dispersed media.