High-Power and Low-Noise Mode-Locking Operation of Al-Quaternary Laser Diodes

We report on the design and experimental evaluation of AlGaInAs/InP multiquantum well epistructures for mode-locked emission at 1.5 μm. We show that mode-locked lasers fabricated on an optimized three quantum well active region with a low optical confinement factor deliver pulses with increased peak power and stability over a much wider biasing range than those fabricated using a standard five quantum well design. Sonogram measurements indicate that sub-ps symmetrical pulses with a substantially reduced linear blue chirp are generated up to nearly three times the laser current threshold.