Investigations on Nonlinear Polariton Dispersion in Ferroelectric Superlattice System

Abstract

Superlattices have drawn considerable attention in the recent years. In this work, the behaviour of polaritons in a quantum well superlattice system is analysed both at the centre and at the edge of the brillouin zone using LiNbO3/ LiTaO3 as an example. The significance of the polariton modes are analysed. New modes due to nonlinearity on the polaritonic gap, where the propagation of electromagnetic wave is forbidden, are obtained in the system as suggested by some recent literature. The variation of frequency with the thickness is also studied.