Bezryadina, AnnaNeshev, DragomirDesyatnikov, Anton SYoung, JackChen, ZhigangKivshar, Yuri2009-06-052010-12-202009-06-052010-12-20Optics Express 14.18 (2006): 8317-83271094-4087http://hdl.handle.net/10440/425http://digitalcollections.anu.edu.au/handle/10440/425We study interaction of a discrete vortex with a supporting photonic lattice and analyze how the combined action of the lattice periodicity and the medium nonlinearity can modify the vortex structure. In particular, we describe theoretically and observe in experiment, for the first time to our knowledge, the nontrivial topological transformations of the discrete vortex including the flipping of vortex charge and inversion of its orbital angular momentum. We also demonstrate the stabilizing effect of the interaction with the so-called “mixed” optically-induced photonic lattices on the vortex propagation and topological structure.11 pages"OSA will grant the authors permission to deposit the publisher’s pdf from their Optics Express articles into the repository with the proper citation (reference number or journal /volume/page/year citation)." - from email received from Authorized Agent, The Optical Society, 27/05/10nonlinear optics, transverse effects inself-action effects2006-09-0110.1364/OE.14.0083172015-12-08