Dynamic light transport through scattering and absorbing media: a study based on the radiative transfer equation

We describe a method to solve the time-dependent radiative transfer equation in order to study the propagation of light pulses through scattering media. This method is based on using the discrete ordinate method in the frequency domain. In imaging applications, the diffusion approximation is widely used but the definition of the diffusion coefficient depends of the form of these approximations. In particular, the dependence on absorption is different. We also present a novel derivation of the diffusion coefficient derived from an asymptotic analysis of the radiative transfer equation. This diffusion coefficient is not restricted to low absorption of the medium.