Calculation of the anisotropic component of light in a dissipative medium with a linear scattering phase function

The study of the propagation of photons systematically moving to the depth of a random dissipative medium is continued. Such photons reach a predetermined depth without changing the sign of the momentum projection p(z) along the internal normal to the surface of the substance. These photons form a so-called anisotropic component of the radiation intensity. It is demonstrated that the sign change of the momentum projection p(z) owing to the photon transition from the lower hemisphere to the upper one (the probability of this event differs from zero) is equivalent to introducing additional absorption in the equation for the anisotropic component of radiation. The effective absorption strongly affects virtually all characteristic parameters of the spatial-angular distribution of photons. An analytical expression for the intensity of the anisotropic component of the diffuse scattered radiation is obtained for the case when the law of single scattering is linear in terms of the scattering angle. Such a scenario can be realized in media with small-scale (in comparison with the wavelength) scattering centers. The effect of the mean cosine of the single-scattering angle on the zero and first azimuthal harmonics of the radiation intensity is analyzed. The behavior of the harmonics is studied at small and large depths. The most probable propagation angles of photons are calculated for various depths. The rotation of the body of brightness is demonstrated for the anisotropic component of the light intensity. The depth decay coefficient is determined. A simple analytical expression for the mean cosine of the anisotropic component of radiation and the probability of photon transition from the lower hemisphere to the upper one in the depth mode is derived. The results obtained for the anisotropic component of radiation are compared to similar results obtained for the total intensity.