Non-linear Effects on Polariton Modes in Superlattice Systems

Abstract

Several optical properties of crystals are modified due to non-linearity associated with high intensity of the incident radiation. In the present work, we explore the possibilities of nonlinear effects in the optical parameters especially in the polariton behaviour of certain optoelectronic materials like LiNbO₃ and LiTaO₃. A new mode on the polaritonic gap, where the propagation of electromagnetic wave is forbidden, is obtained in these materials as suggested by some recent literature. It is also extend to superlattice system. The effect on non-linear interactions of phonon polaritons in LiNbO₃/LiTaO₃ superlattices is discussed. Various modes of polariton dispersion is also analyzed.