Intracavity stabilization of broad area lasers by structured delayed optical feedback

The influence of structured delayed optical feedback (SDOF) on a broad area laser is investigated experimentally. SDOF is realized with a miniature-sized convex external mirror. The setup takes into account the small time scales involved in semiconductor laser dynamics by employing short external resonator lengths. Careful choice of the feedback parameters leads to a narrow single-lobe farfield even at high pump currents. The experimental results confirm earlier microscopic dynamic simulations by O. Hess et al. predicting that SDOF might be capable of stabilizing the emission of broad area lasers.