General linear response theory of polaritons in binary superlattices

Abstract

A general fully retarded theory of polaritons in a two-component (binary) dielectric superlattice is developed using linear response techniques. The polariton Green functions of the superlattice are derived explicitly assuming arbitrary forms for the isotropic dielectric functions of the superlattice components. From these Green functions the dispersion relations and spectral intensities for transverse electric and transverse magnetic polariton models in the superlattice may be deduced. Some numerical illustrations are included. The results of the general theory are verified to yield correct forms in various known special cases. The authors also deduce the form of the Green functions in the nonretarded approximation, anticipating subsequent application of the theory to light scattering by low-frequency plasmon-polaritons in semiconductor superlattices.