title: Stable three-dimensional spinning optical solitons supported by competing quadratic and cubic nonlinearities.
abstract: We show that the quadratic interaction of fundamental and second harmonics in a bulk dispersive medium, combined with self-defocusing cubic nonlinearity, gives rise to completely localized spatiotemporal solitons (vortex tori) with vorticity s=1. There is no threshold necessary for the existence of these solitons. They are found to be stable if their energy exceeds a certain critical value, so that the stability domain occupies about 10% of the existence region of the solitons. On the contrary to spatial vortex solitons in the same model, the spatiotemporal ones with s=2 are never stable. These results might open the way for experimental observation of spinning three-dimensional solitons in optical media.
authors.affiliation: Department of Theoretical Physics, Institute of Atomic Physics, P.O. Box MG-6, Bucharest, Romania.
authors.forename: D
authors.initials: D
authors.lastname: Mihalache
authors.forename: D
authors.initials: D
authors.lastname: Mazilu
authors.forename: L-C
authors.initials: LC
authors.lastname: Crasovan
authors.forename: I
authors.initials: I
authors.lastname: Towers
authors.forename: B A
authors.initials: BA
authors.lastname: Malomed
authors.forename: A V
authors.initials: AV
authors.lastname: Buryak
authors.forename: L
authors.initials: L
authors.lastname: Torner
authors.forename: F
authors.initials: F
authors.lastname: Lederer