Hybrid Silicon Colliding-Pulse Mode-Locked Lasers With On-Chip Stabilization

We investigate the design of hybrid silicon colliding-pulse mode-locked laser diodes and the dependence on quantum well design. We show the reduction in microwave linewidth using two techniques. First, reducing the number of quantum wells reduces the confinement factor thereby lowering the spontaneous emission contribution to the linewidth. Second, a ~4-cm long on-chip feedback cavity is used to provide optical feedback to stabilize the laser and further reduce the linewidth. The linewidth achieved at 17.36 GHz using the above two techniques is 29 kHz.