Mode locking of semiconductor lasers in a coupled-cavity configuration with a strongly coupled empty auxiliary cavity

Mode locking of semiconductor lasers in a coupled-cavity configuration with an empty auxiliary cavity is studied theoretically. The empty auxiliary cavity, when strongly coupled to the main cavity, is found to influence the pulsation situation significantly. The predicted pulse widths and chirp parameters in the steady state are in good agreement with the experimental measurements. The influences of the linear phase shift induced by the cavity-length variation and the self-phase modulation in the main cavity on the pulsation are also briefly discussed.