Coexistence of in-phase and out-of-phase dynamics in a multimode external-cavity laser diode operating in the low-frequency fluctuations regime - art. no. 061803

We study the dynamics of a multimode laser diode with delayed optical feedb ack operating in the low-frequency fluctuations regime. We show that a mult imode extension of the Lang-Kobayashi equations that takes into account spo ntaneous emission noise predicts two qualitatively different behaviors of t he laser on the picosecond time scale. Individual modes of the laser can em it pulses in-phase or oscillate out-of-phase, depending on the operating pa rameters. The corresponding statistical distributions are in good agreement with two recent experiments.