MONOLITHIC COLLIDING PULSE MODE-LOCKED SEMICONDUCTOR-LASERS

In this paper we investigate the temporal and spectral properties of m onolithic colliding pulse mode-locked (CPM) quantum-well lasers. A lar ge-signal model for the CPM laser is derived, which explains the mode- locking behaviour of both passively and hybridly mode-locked CPM laser s. The pulse-shaping and wavelength chirp of the CPM pulses are found to be the result of a complicated interplay between the gain and satur able absorber dynamics. The experimentally measured pulse width depend ence upon variation of gain current and applied reverse bias on the sa turable absorber is explained by fast gain dynamics. The experimentall y observed broadening of the optical power spectrum with gain current is found mainly to be due to the self-phase modulation iri the gain se ctions.