Excitability of chaotic transients in a semiconductor laser

Using a semiconductor laser with integrated optical feedback, excitability of high-dimensional chaotic transients is demonstrated in a continuous and autonomous system. The generic phase-space portrait behind our observation consists in a boundary crisis of a chaotic attractor with a saddle born in a saddle-node bifurcation of continuous-wave states. The excitation of the chaotic transients, performed by short optical pulses, exhibits a distinct threshold as well as a refractory time. The escape from the chaotic saddle is strictly single-exponential and the escape time is an inverse-power function of the the distance to the boundary crisis with —despite of high dimensionality— a critical exponent close to unity. The device is capable of emitting pulses with a delay that is more than two orders of magnitude longer than the time scale of the internal carrier-photon dynamics.