We analyse the dynamics of a self-pulsating semiconductor laser with optical feedback. Without re-injection of light the laser displays periodic oscillations. At very weak feedback levels we observe an amplitude instability whose frequency increases with the feedback level until the laser enters the low frequency fluctuation regime commonly observed in cw lasers with optical feedback. We show that such behaviour can be observed within the framework of the Lang-Kobayashi equations for self-pulsating semiconductor lasers.
- External cavity
- Relaxation oscillation