Statistical Properties of low Frequency Fluctuations under Single Mode Operation in DFB lasers: Experiments and Modelling

Extensive experimental and numerical investigations of feedback-induced instabilities in single-mode distributed-feedback lasers are presented that confirm the basic assumptions of the Lang Kobayashi model. We give experimental evidence of the occurrence of low-frequency f luctuation (LFF), alternation between LFF and stable emission, and coherence collapse during single-mode operation of the laser. We have obtained quantitative agreement between modeling and experiment in long-time statistical investigations of the time intervals between subsequent LFF dropouts. In particular, we show that even the dependence of the dynamics on the injection current, which results in a scaling law, is quantitatively identical in modeling and experiment.