Suppression of low-frequency fluctuations and stabilization of a semiconductor laser subjected to optical feedback from a double cavity: theoretical results

We demonstrate numerically that low-frequency fluctuations (LFF's) observed in a laser diode subjected to a first optical feedback with a short delay are suppressed by means of an adequate second optical feedback. The general idea of this technique is based on the observation that second feedback ca n suppress the antimodes that are responsible for the crises in the LFF reg ime. Furthermore, we observe that the second optical feedback can steer an unstable laser that is biased near threshold into a stable regime. (C) 1999 Optical Society of America.