Soliton dynamics in a semicondutor cavity soliton laser with broken translational symmetry

In a vertical cavity semiconductor laser with an intracavity saturable absorber, cavity solitons (CS) behave as localized micro-lasers freely placed in the transverse plane, sitting over a zero-intensity, non-lasing background, thus realizing a cavity soliton laser (CSL). We show that in this system there are parametric conditions for which the CS moves spontaneously in the transverse plane, with a velocity of the order of some μm/ns, depending on the parameters of the system. Key parameters ruling the dynamical instability causing CS motion are the pump and the ratio between the non-radiative decay rates of carriers belonging to the active and passive media.