Rayleigh light scattering by large-scale inhomogeneities in filled liquid crystals

Abstract

This paper presents a theoretical study of differential and total light scattering cross-sections in liquid crystals containng small hard macroscopic spherical or cylindrical particles, using the naomalous-diffraction approach. The light scattering is normally governed by director inhomogeneity around teh separate particles. When the particles form a network the scattering is controlled by the director domain structure. We consider the influence of particle shape and size, the type of director anchoring on the particle surface and light polarization. Our principal findings are that: (a) for a so-called 'dipole' director configuration around the particle, the light scattering is predicted to be approximately two orderes of value stronger than for a so-called 'Saturn ring' configuration; (b) incident light polarizred parallel to the scattering plane gives rise to a stronger scattered angular dependnece than light polarized perpendicular to it; (c) when the inclusions are cylindrical the light scattering is relatively stronger at lwo scattering angles than when the inclusions are spherical; (d) for a particle network, the nature of the network domain orientational distribution influences the intenstiy of light scattering, but has little effect on its angular dependence.