Quadratic solitons as nonlocal solitons

This study investigates the effect of the nonlocality aspects of /spl chi//sup (2)/ solitons on properties of bright and dark solitons and formation of the bound states of solitons. We consider two beams- fundamental wave (FW) with an amplitude /spl phi//sub 1/ and its second harmonic with an amplitude /spl phi//sub 2/ propagating in a quadratic nonlinear medium under conditions for type I phase-matching.