To the theory of surface plasmon-polaritons on metals covered with resonant thin films

The experimental investigations of plasmon-polaritons propagating along the metal surface can be found in numerous published papers. In this paper, the theory of the dispersion of the surface plasmon-polaritons propagating along the surface of metals covered with dielectric resonant thin films, developed in [1], [2] and [3], has been made more precise and complete. The calculations presented in this work enable now to evaluate not only the qualitative dependence of the surface plasmon-polaritons splitting value upon the layer thickness l   and resonant wavelength λλ, but also to determine the numerical value of the gap. The layer thickness l   is assumed to be l⪯¡λl⪯¡λ and we also assume that the film thickness is much larger than the lattice constant. To demonstrate the results of the theory we consider the plasmon-polariton dispersion relations when metal is covered with the layer comprising molecular J-aggregates.