The aim of this work is to contribute to a better determination of the optical parameters for dense scattering media. We study the interaction of femtosecond polarized light pulse with a scattering medium considering Monte Carlo simulation. The Monte Carlo scheme is based on temporal photon tracking, including a pseudo Monte Carlo approximation associated to two small detectors in forward and backward directions. The statistical scattering properties are derived from temporal phase matrices, which are evaluated through a scanning of frequency associated to the Lorenz-Mie theory. We specially focused our attention on solid rocket motor modelling. In such scattering medium, large optical thickness, various bimodal particle size distributions and concentration gradients could be observed. Moreover, such media consists in a suspension of big particles (typically 100 μm diameter). The understanding of the scattering process of such particles needs the introduction of Debye modes. We will explain the contribution of these modes and give an example with a numerical application.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.