Excitability mediated by localized structures

This work reports on a new regime of excitability associated to the existence of localized structures in a nonlinear optical system. Findings emphasize that, in absence of spatial degreed of freedom, the system described by the partial differential equation is not an excitable system. The system exhibits excitability only after a localized structure has undergone a Hopf and a saddle-loop bifurcation. Finally, this study shows that all this scenario is organized by a co-dimension two Takens-Bogdanov bifurcation point.