Attenuation and forward scattering of short-duration laser radiation in a strongly scattering medium

An experimental investigation was made of the dependence of the optical density of a layer of a strongly scattering medium on its thickness in the case of a model aqueous milk solution. The radiation sources were IR lasers generating pulses of various (from nanosecond to femtosecond) durations. The dependences of the attenuation coefficients of such pulses on the solution concentration were determined for low and high optical densities of the solution layer. Estimates were obtained of the absorption and scattering coefficients of the medium. A modification of the two-flux Kubelka — Munk model was used to derive an expression describing the dependence of the transmission of a solution layer on its parameters when radiation detectors with a finite angular aperture are used. A comparison of the calculations and experiments revealed a forward scattering anisotropy of short-duration laser radiation in an aqueous milk solution.