Depolarization of light in tissue phantoms - effect of a distribution in the size of scatterers.

We show that the depolarization behavior of light on propagation through a sample having a mixture of suspension of monodisperse polystyrene microspheres of two different sizes (mean diameter 0.11microm and 1.08 microm) is dominated by the smaller of the two scatterers. In contrast the estimates for the anisotropy parameter (g) for this sample, obtained from goniophotometric measurement, are observed to be closer to the value corresponding to the larger of the two scatterers. These results imply that the depolarization behavior of light in biological tissue (having a distribution of scatterer size) would be different from that of a matched monodisperse scattering sample having the same value of anisotropy parameter (g) and optical thickness (tau = micros x d, micros is scattering coefficient and d being the physical thickness).