Time-domain analysis of fiber grating semiconductor laser operation in active mode-locking regime

We analyze in detail the mode-locking characteristics of fiber grating semiconductor lasers using a split-step time-domain approach. The accuracy of the simulations is demonstrated by the capability of the numerical code to describe the fine structure of the resonance peak spectral splitting (RPSS) of the intensity modulation (IM) response near the FSR modulation frequency with a very good agreement with analytical results reported in the literature. The mode-locking (ML) frequency range was found to be closely related to the IM characteristic shapes around the resonance peak. The ML pulse characteristics and frequency range of Gaussian gratings with different apodization and dispersion characteristics have been reported as an example.