Soliton multistability as a result of double-resonance wave mixing in chi((2)) media

We investigate analytically and numerically the existence and stability pro perties of three-wave solitons resulting from double-resonance (type I plus type II) parametric interaction in a purely quadratic nonlinear medium. Th e existence of a family of stable solitons for the double-resonance model i s demonstrated in a broad parameter range. Moreover, these solitons are sho wn to exhibit multistability, a feature that is potentially useful for opti cal switching applications. Finally, we find and present a novel family of quasi solitons. (C) 1999 Optical Society of America.