A Model for a Quantum-Dot Gain-Lever Mode-Locked Laser

An alternative explanation of achieving passive mode-locking in a quantum-dot (QD) laser without a dedicated saturable absorber section is proposed. The method employs an analytical model based on the net gain modulation within the cavity. Two differentially pumped sections, operated in forward bias, may utilize the differential gain contrast between them to enable pulse formation. The large differential gain contrast available in QD media and the relative ease with which such devices can be fabricated extend the utility of this methodology for the development of a QD gain-lever mode-locked laser as a next generation optical source. Alternative cavity configurations that exclude a dedicated saturable absorber section and the concomitant reduction of intracavity losses provides another path in the development of short cavity lasers with high pulse repetition rates.