Abstract
The sequence of phenomena that lead from a narrow linewidth state to coherence collapse in semiconductor lasers for an increasing level of optical feedback has been identified. Undamping of the relaxation oscillations, which is shown to be accurately predicted by an analytical stability analysis, initializes the route to chaos, but the laser generally enters quasiperiodic and frequency-locked states before ending up in the chaotic state of coherence collapse. The analysis identifies the laser parameters which are relevant for reducing the feedback sensitivity.