Separation and analysis of forward scattered power in laboratory measurements of light beam transmittance through a turbid medium.

In laboratory measurements of the transmittance of a light beam through a diffusing medium (water plus latex spheres), a distinction between the attenuated beam power and the received forward scattered power was made possible by the use of a transmissometer whose receiver has a variable field of view. The dependence of the received scattered power on the FOV angle and on the medium optical depth was analyzed. The deduced separated contributions of first- and second-order scattering, as well as the total received scattered power, were compared to the results of calculations.