ANALYTICAL CALCULATION OF STATIONARY LIGHT FIELDS IN THE PROPAGATION OF LASER-RADIATION IN RANDOMLY INHOMOGENEOUS 2D MEDIA WITH A MODEL TETRADIRECTIONAL SCATTERING PHASE FUNCTION

In this paper, we use the classical transfer equation to analytically calculate light fluxes in the case of the normal incidence of a statio nary laser beam on the surface of a semi-infinite random 2D medium wit h a model tetradirectional scattering phase function of separate scatt ering centers. An algorithm for modeling real optical phase functions is thoroughly described. An appropriate modeling procedure is performe d for the widespread Henyey-Greenstein phase function. We determine th e law of spreading for a narrow laser beam with the depth and define t he effective width of the reflected light flux. Asymptotic behavior of the radiation intensity is investigated in the longitudinal and trans verse directions relative to the axis of the incident beam. We analyze the total coefficient of reflection of light from a semi-infinite med ium irradiated by a broad stationary light flux as a function of the m ain optical characteristics of the medium. The exact solution of the p roblem is compared with the solution obtained with the use of the tetr adirectional scattering phase function for isotropic scattering from a n individual scattering center.