Localized structures in a single-mirror feedback system

Summary form only given. It is an interesting feature of localized structures that they react to external perturbations as particle-like entities. In numerical simulations of different model systems localized structures have been shown to drift on phase and intensity gradients of the light field, to interact with their neighbors and to be very sensitive with respect to small variations of the background intensity. In our experiment we investigate these phenomena in a single mirror setup and demonstrate that phase gradients due to self induced lensing in a limited beam play a crucial role. We use sodium vapor as the nonlinear medium which can be produced in good optical quality without short-scale inhomogeneities.