Definition of the diffusion coefficient in scattering and absorbing media.
We revisit the definition of the diffusion coefficient for light transport in scattering and absorbing media. From an asymptotic analysis of the transport equation, we present a novel derivation of the diffusion coefficient, which is restricted neither to low absorption nor to a situation in which the specific intensity is quasi-isotropic. Our result agrees with previous expressions of the diffusion coefficient in the appropriate limit. Using numerical simulations, we discuss the implications of the proper choice of the diffusion coefficient for time-dependent transport.
Elaloufi
Rachid
R
Laboratoire d'Energétique Moléculaire et Macroscopique, Combustion, Centre National de la Recherche Scientifique, 92295 Châtenay-Malabry Cedex, France.
Carminati
Rémi
R
Greffet
Jean-Jacques
JJ
D004058:Diffusion; D008027:Light; D008962:Models, Theoretical; D055095:Optics and Photonics; D012542:Scattering, Radiation