3D cavity light bullets in a nonlinear optical resonator

We consider a nonlinear ring cavity resonator filled by a saturable absorber and driven by a plane wave field. Under the slowly varying envelope and paraxial approximation, we introduce a quite general approach to the analysis of the spatio-termporal dynamics of the coherent field beyond the mean-field limit, fully taking into account propagation, diffraction and the boundary conditions imposed by the cavity. We study the stability of the stationary solutions versus spatially modulated perturbations, and identify regimes where we observe total radiation confinement and the formation of 3D localised bright structures. At difference from freely propagating light bullets, here the self-organization proceeds from the combination of diffraction, nonlinearity and resonator feedback. Such cavity light bullets (CLBs) endlessly travel the cavity roundtrip and can be independently manipulated. These characteristics makes CLBs natural candidates for optical bits and for particle-like optical probes.