Temporal and Spatial Laser Instabilities

Recent experiments have shown optics to be a fertile testing ground for nonlinear physics and dynamics. We show that lasers can represent to fine details the dynamics and chaos of the Lorenz model as a classical case of nonlinear temporal behaviour. Spatial instabilities such as pattern formation, spatial symmetry breaking, as well as spatial multistability have recently been predicted and first experiments have confirmed the predictions. We point to the relation of the recently demonstrated spatially bistable helical wave laser emission with the recently predicted ‘optical defect’ in the form of vortices, and give the first tentative experimental evidence for arrays of helical waves.