title: Optical vortex solitons in parametric wave mixing
abstract: 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.
authors.affiliation: Optical Sciences Center, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200, Australia.
authors.initials: TJ
authors.lastname: Alexander
authors.initials: YS
authors.lastname: Kivshar
authors.initials: AV
authors.lastname: Buryak
authors.initials: RA
authors.lastname: Sammut