Spatial Solitons and Induced Kerr Effects in Quasi-Phase-Matched Quadratic Media

Abstract
We show that the evolution of the average intensity of cw beams in a quasi-phase-matched quadratic (or χ(2)) medium is strongly influenced by induced Kerr effects, such as self- and cross-phase modulation. We prove the existence of rapidly oscillating solitary waves (a spatial analog of the guided-center soliton) supported by the quadratic and induced cubic nonlinearities.