Bistability between different localized structures in nonlinear optics

The bistability of different localized structures (LS) coexisting for the same parameter values in an extended system was investigated. The bistability was carried out in a nonlinear optical interferometer and was fully confirmed by numerical simulations. It was observed that the existence of each kind of LS was kept in relation to a corresponding delocalized pattern. The mechanism of lying at the basis of LS bistability was the existence of two modulational instabilities, giving rise to two different patterns of different amplitude and symmetry.