13 research outputs found
Quadratic solitary waves in a counterpropagating quasi-phase-matched configuration
We demonstrate the possibility of self-trapping of optical beams by use of
quasi phase matching in a counterpropagating configuration in quadratic media.
We also show the predominant stability of these spatial self-guided beams and
estimate the power level required for their experimental observation.Comment: 3 pages, 4 figure
Stability of spinning ring solitons of the cubic-quintic nonlinear Schrodinger equation
We investigate stability of (2+1)-dimensional ring solitons of the nonlinear
Schrodinger equation with focusing cubic and defocusing quintic nonlinearities.
Computing eigenvalues of the linearised equation, we show that rings with spin
(topological charge) s=1 and s=2 are linearly stable, provided that they are
very broad. The stability regions occupy, respectively, 9% and 8% of the
corresponding existence regions. These results finally resolve a controversial
stability issue for this class of models.Comment: 10 pages, 5 figures, accepted to Phys. Lett.
Higher-order nonlinear modes and bifurcation phenomena due to degenerate parametric four-wave mixing
We demonstrate that weak parametric interaction of a fundamental beam with
its third harmonic field in Kerr media gives rise to a rich variety of families
of non-fundamental (multi-humped) solitary waves. Making a comprehensive
comparison between bifurcation phenomena for these families in bulk media and
planar waveguides, we discover two novel types of soliton bifurcations and
other interesting findings. The later includes (i) multi-humped solitary waves
without even or odd symmetry and (ii) multi-humped solitary waves with large
separation between their humps which, however, may not be viewed as bound
states of several distinct one-humped solitons.Comment: 9 pages, 17 figures, submitted to Phys. Rev.
Soliton Multistability as a Result of double-resonance Wave Mixing in c (2) Media
We investigate analytically and numerically the existence and stability properties of three-wave solitons resulting from double-resonance (type I plus type II) parametric interaction in a purely quadratic nonlinear medium. The existence of a family of stable solitons for the double-resonance model is demonstrated in a broad parameter range. Moreover, these solitons are shown to exhibit multistability, a feature that is potentially useful for optical switching applications. Finally, we find and present a novel family of quasi solitons
Optical vortex solitons in parametric wave mixing
We analyze two-component spatial optical vortex solitons supported by parametric wave mixing processes in a nonlinear bulk medium. We study two distinct cases of such localized waves, namely, parametric vortex solitons due to phase-matched second-harmonic generation in an optical medium with competing quadratic and cubic nonlinear response, and vortex solitons in the presence of third-harmonic generation in a cubic medium. We find, analytically and numerically, the structure of two-component vortex solitons, and also investigate modulational instability of their plane-wave background. In particular, we predict and analyze in detail novel types of vortex solitons, a "halo-vortex," consisting of a two-component vortex core surrounded by a bright ring of its harmonic field, and a "ring-vortex" soliton which is a vortex in a harmonic field that guides a ring-like localized mode of the fundamental-frequency field