Localization of light in three-dimensional random dielectric media

Abstract

A systematic approach to the localization of light waves in three-dimensional dielectric media is developed. A general definition of localization of electromagnetic waves is proposed and its consequences are elaborated. A significant amount of localization of the energy density of the electromagnetic field is predicted in finite systems of randomly distributed dielectric particles modeled by dipoles linearly coupled to the electric field of the incident wave. Although in this case it is not possible to achieve perfect localization, the predicted phenomenon is experimentally indistinguishable from a complete localization. Our approach is based directly on the Maxwell equations; the vector character of the electromagnetic waves is fully taken into account. The concepts presented in our previous paper [M. Rusek and A. Orłowski, Phys. Rev. E 51, R2763 (1995)] are now generalized to the three-dimensional case. Instead of using the Kirchhoff integral formula for scalar waves, we now analyze light scattering by pointlike dielectric particles as the special case of general considerations dealing with elastic scattering of electromagnetic waves by arbitrary localized charges and currents.