Stability of weakly nonparaxial spatial optical solitons in a medium with a Kerr nonlinearity

A variant of perturbation theory is developed to determine the characterist ics and stability of transversely two-dimensional spatial solitons in a Ker r medium under conditions of small deviations from paraxial. Distributions of the transverse and longitudinal components of the soliton electric and m agnetic fields are obtained. It is shown that the power of a nonparaxial so liton in a Kerr medium increases as the propagation constant increases. A l inear analysis is made of soliton stability. In addition to confirming stab ility, this analysis revealed "internal modes" of nonparaxial solitons and their characteristics were determined. (C) 2000 MAIK "Nauka/Interperiodica" .