Synchronization phase diagrams of monolithic colliding pulse-modelocked lasers

We present phase diagrams of colliding pulse mode locked (CPM) InGaAsP QW laser operation relevant to the ability to synchronize the repetition rate to an external clock. A three-dimensional parameter space of gain currents, absorber bias, and RF frequency is explored using an automated test set up.

We find regions of modelocking, self-pulsation, and incomplete modelocking/CW lasing. We show that the modelocked region is asymmetric in RF frequency; i.e., the pulse repetition rate can be slowed down more easily than speeded up.