We show that, contrary to common wisdom, the maximum gain mode of semiconductor lasers subject to optical feedback is always stable. The minimum linewidth mode is shown to be subject to a Hopf bifurcation associated with destabilizing the relaxation oscillations. This explains the experimental observation of narrow-linewidth, single-mode diode lasers operating with high optical feedback.

• Received 25 July 1995

DOI:https://doi.org/10.1103/PhysRevA.52.R3436