Prediction of unique solitary-wave polaritons in quadratic—cubic nonlinear dispersive media

Abstract

A single terahertz electromagnetic pulse that interacts with transverse-optic phonons in a crystal medium is found to have unique features in the presence of both the second- and the third-order nonlinearities. Specifically, for a short pulse with a broad plateau, coexistence is predicted between a bright and a dark polariton. Analytical expressions for the cross-sectional shape and the FWHM of the polariton pulse are derived.