Investigation of the Carrier Dynamics and Electrical Pumping Behavior of InAs/GaAs Quantum Dot Lasers

Semiconductor quantum dot (QD) based electrically pumped lasers recently show great promise as an alternative to the conventional bulk and quantum well lasers. For optical fiber communications, InAs/GaAs based 1.3 μm lasers show low cost, low power consumption, high-performance on long-distance transmission. To increase the performance of QD based lasers, it is necessary to develop a comprehensive model incorporating different important physical phenomena that exist in the real laser devices. In this work, the behavior of InAs/GaAs QD lasers upon electrical pumping conditions are investigated through rate equations modeling. The model includes four energy levels in which three of them are considered for lasing operation. First, the temporal dynamics of the carrier and photon densities of these three energy levels are investigated by changing the injection current and spontaneous recombination time. Then, the performance of the InAs/GaAs QD laser is investigated in terms of internal quantum efficiency and intrinsic gain phenomenon. This analysis helps to explore the inherent properties of QD lasers, which is necessary for designing efficient electrically pumped practical InAs/GaAs based QD lasers.