On radiation scattering by a particle located in a regularly inhomogeneous medium

The scattering characteristics of a spherical particle placed into a regularly inhomogeneous medium are studied. It is shown that the inhomogeneity of the medium surrounding the particle substantially changes the scattering pattern of a light wave compared to scattering of light by a particle in a homogeneous medium considered in the classical theory. The expressions for the scattering amplitude are obtained for the conditions when an inhomogeneous medium can be represented as a defocusing or focusing channel. It is shown that the defocusing action of the medium is manifested in a significant broadening of the scattering amplitude and its shift compared to the classical case. The focusing of scattered radiation by the medium can cause both broadening and narrowing of the scattering amplitude, as well as periodic variations in its position. The influence of regular refraction on the propagation of a radiation beam in the scattering medium is estimated.