Light propagation in structural anisotropic media in the steady-state and time domains.

The determination of the reduced scattering and absorption coefficients of structural anisotropic turbid semi-infinite media and slabs was investigated in the steady-state and time domains. Forward calculations were performed with a Monte Carlo model that considered both cylindrical scatterers aligned in different directions as well as scatterers that were described by a rotationally symmetric scattering function. Analytical solutions of the isotropic and anisotropic diffusion equations were applied to retrieve the optical properties. It was found in the steady-state and time domains that the solutions of the anisotropic diffusion equation have systematic errors compared to the Monte Carlo simulations not only for small distances from the source. However, it is shown that in the time domain it is possible to retrieve useful values for the optical properties using the isotropic and the anisotropic diffusion equations.