title: Observation of self-induced optical vortex precession.
abstract: We report on the observation of self-induced precession of an optical vortex as a result of the nonlinear interaction between light and liquid crystals. The phenomenon corresponds to an instability for the spin-orbit interaction of light that manifests as a spontaneous axial symmetry breaking, which leads to the orbital motion of the optical vortex around the beam propagation. A nonlinear spin Hall effect of light is experimentally identified, thereby unveiling an original demonstration of spin to extrinsic orbital light angular momentum self-conversion.
authors.affiliation: Université Bordeaux, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798, F-33400 Talence, France and CNRS, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798, F-33400 Talence, France.
authors.forename: Mohamed El
authors.initials: ME
authors.lastname: Ketara
authors.affiliation: Université Bordeaux, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798, F-33400 Talence, France and CNRS, Laboratoire Ondes et Matière d'Aquitaine, UMR 5798, F-33400 Talence, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Brasselet