title: Steady-state vortex-screening solitons formed in biased photorefractive media.
abstract: We report the observation of steady-state photorefractive vortex-screening solitons. As a singly charged circular vortex nested on a broad beam propagates through a biased strontium barium niobate crystal, it self-traps in both transverse dimensions despite the inherent anisotropy of the photorefractive nonlinearity. When the vortex beam is a doughnut-shaped narrow beam, it breaks up into two elongated slices (with a self-defocusing nonlinearity) or into two focused filaments (with a self-focusing nonlinearity). We demonstrate the optical guidance of a probe beam in a circular waveguide induced by the self-trapped vortex.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: M F
authors.initials: MF
authors.lastname: Shih
authors.forename: M
authors.initials: M
authors.lastname: Segev
authors.forename: D W
authors.initials: DW
authors.lastname: Wilson
authors.forename: R E
authors.initials: RE
authors.lastname: Muller
authors.forename: P D
authors.initials: PD
authors.lastname: Maker