Nonlinear Dynamics in Semiconductor Lasers - Abstract
Lüdge, Kathy
Passively mode-locked semiconductor lasers are inexpensive sources of short optical pulses with high repetition rates. However, different geometries of the laser cavity and the position of the gain and the absorber sections can change the emitted pulse trains. We explore different dynamic regimes of the mode-locked laser operation and characterize the performance in terms of the timing jitter of the emitted pulses. Different laser configurations will be explored. In detail we investigate the effects of external optical feedback loops, V-shaped cavities and monolithically integrated tapered gain sections on the emitted pulse trains. For the simulations of the integrated device we combine a traveling-wave model for the electric field propagation with microscopically based charge-carrier rate equations, while we use a delay differential equation model for the external and the V-shaped cavities. Ultra short, high power pulses with excellent pulse train stability are found for the tapered gain sections. Here, trailing edge pulses can be suppressed by optimized device geometries, i.e., saturable absorber position and angle of the tapered gain section. Further, we find the V-shaped cavity set up to be suitable for generating very short pulses with very low timing jitter, however, we also find a high degree of multistability and new solutions like double pulse emission which can dramatically change the performance of the device.