Dispersive self-Q-switching in DFB lasers-theory versus experiment

The single-mode model of dispersive self-Q-switching is extended to lasers containing a phase tuning section. The parameter set used for modeling is taken from independent measurements on existing self-pulsating devices. Detuning of the Bragg wavelengths by current induced heating is found, and this effect is included in the model. Calculated self-pulsation characteristics were compared quantitatively with experimental results on the device. A very good correspondence between theory and experiment is obtained, e.g., for conditions generating self-pulsations and for the frequency-current dependence. Dispersive self-Q-switching thus is confirmed as the responsible mechanism for high frequency DFB type self-pulsations. The modeling further shows that the delay between the stimulated emission within the device and the radiation of photons from the facets plays an important role for keeping the pulsations running.