Nonlinear Dynamics in Semiconductor Lasers - Abstract

Tronciu, Vasile

Analyzing limits of linewidth reduction of a DFB laser by a resonator

Vasile Tronciu, Hans Wenzel, and Hans Juergen Wuensche Stimulated by recent experiments, the link between chirp reduction and destabilizing bifurcations is investigated theoretically. Both features are determined from appropriately combining the known dispersions of the reflectivities of laser and resonator. The feedback phase for optimum chirp reduction is determined. The coupling strength between laser and resonator and the finesse of the resonator are regarded as the main bifurcation parameters. Self-sustaining pulsations in a finite region of medium feedback strength are found to separate two regions of stable chirp reduction. In the weak-feedback region, the chirp reduction is also weak, unless the finesse is extremely large. A moderate finesse suffices at strong feedback. However, the theory is to be improved in this regime, because the assumed closeness of the inversion to the threshold of the solitary laser is no more valid.