ON THE LOCKING RANGE OF HYBRIDLY MODE-LOCKED SEMICONDUCTOR-LASERS

We theoretically investigate the locking range of hybridly mode-locked semiconductor lasers with a DBR section as a reflector. The DBR coupl ing constant and length are crucial in determining the locking range3. At constant pulse width, the tuning range of the repetition frequency can be increased by a factor of 3 by using a strongly coupled, long D BR rather than a short and weakly coupled DBR. For a 30 GHz cavity and a pulse width of 5 ps, a locking range of 2.5% is predicted after opt imization. We explain the increase in the locking range as a consequen ce of the dispersion inherent to a DBR. In addition, the pulses are fo und to be asymmetric, depending on the DBR parameters.