Application of transfer matrix method for detailed description of phonon-polariton states in semiconductor superlattices

On the base of the transfer matrix formalism the dispersion of phonon polaritons in finite and infinite semiconductor SLs was calculated. The account of retardation effects leads to appearance of the additional "dynamical" bandgaps in the interface polariton spectra. The complex reflection coefficients also were calculated for the particular case of GaAs/GaAsP SLs. It is shown that the fine structure of spectra can be described by the method.