Law, Kods JHKevrekidis, P GAlexander, Tristram JKrolikowski, WieslawKivshar, Yuri2015-12-081050-2947http://hdl.handle.net/1885/37730We show that double-charge discrete optical vortices may be completely stable in hexagonal photonic lattices where single-charge vortices always exhibit dynamical instabilities. Even when unstable the double-charge vortices typically have a much weaker instability than the single-charge vortices, and thus their breakup occurs at longer propagation distances.Keywords: Photonics; Discrete vortices; Dynamical instabilities; Optical lattices; Optical vortices; Photonic lattices; Propagation distances; Vortex flow200910.1103/PhysRevA.79.0258012016-02-24