Diffraction of light by absorbing inclusions in solids

The thin-lens approximation is used in an analysis of the diffraction of laser radiation by absorbing inclusions in an isotropic transparent dielectric. Allowance is made for the change in the refractive index of the matrix under the influence of thermal stresses. Asymptotic formulas for the field intensity on the beam axis and for the angular distribution of the intensity in the far zone are obtained for the diffraction by a single inclusion. The diffraction by a phase screen with randomly distributed inhomogeneities of the refractive index is discussed.