Interface plasmon excitations of superlattices with defects

Interface plasmon excitations of superlattices with defects are investigated by the propagation matrix method. A dispersion relation is obtained and is shown to be of sufficient generality. The dispersion curves of the local modes are shown to be dependent upon the thickness and the dielectric constant of the defect layer. The obtained formula generalizes some earlier results obtained by other authors. Several special cases, including the limiting cases of quantum-well layered structures, are discussed and a new mode similar to the Giuliani and Quinn type mode is deduced.