Feedback-induced locking in semiconductor lasers with strong amplitude-phase

The influence of optical feedback on semiconductor lasers has been a widely studied field of research due to fundamental interests as well as the optimization of optical data transmission and computing. Recent publications have shown that it is possible to induce a periodic pulselike output in quantum-dot and quantum-well laser diodes based on the locking of the external cavity modes and the relaxation oscillation frequency. We present an in-depth analysis of this effect. We choose submonolayer quantum dots as a gain system, as these provide a relatively strong amplitude-phase coupling, which has proven to be very beneficial for these locking effects to occur. By introducing an alternative theoretical model, we can correctly reproduce the essential features of the gain system and validate them by comparison to our experimental results. From this starting point we can further explore how the staircase behavior of the oscillation frequency with increasing pump current can be influenced by changing various laser parameters. The staircase behavior is induced by a reordering of the Hopf bifurcations giving birth to the regular pulselike oscillations.

Automated summary

The influence of optical feedback on semiconductor lasers is a widely studied field, recent research has shown that it is possible to induce periodic pulselike output by locking external cavity modes and relaxation oscillation frequency, particularly beneficial for quantum dot systems. The staircase behavior of oscillation frequency can be influenced by changing laser parameters, leading to regular pulselike oscillations through a reordering of Hopf bifurcations.