The Effect of Gain-Coupling on Mode Beatings in Weakly Coupled Two-Section DFB Lasers

The effect of gain-coupling on the predicted self- pulsations in weakly-coupled two section DFB lasers is studied and presented here. The introduction of gain-coupling 1) increases the minimum Bragg detuning needed for self- pulsations, 2) eliminates self-pulsations when the Bragg detuning exceeds the bandstop, 3) reduces the frequency tuning range of self-pulsations, 4) increases the modulation index over most of the tuning range. The study is limited to self-pulsations of the symmetrical mode beating type.