Temperature Performance of Monolithic Passively Mode-Locked Quantum Dot Lasers: Experiments and Analytical Modeling

In this paper, a detailed study is presented on a series of quantum dot (QD) passively mode-locked lasers (MLLs) with variable absorber to gain-section length ratios. The effect of temperature on the stability of pulses emitted from the QD ground state is primarily examined and compared to an analytical model that predicts regions of mode-locking stability for a given device layout. The model correctly predicts the temperatures of maximum operability in each device for a variety of absorber voltages. Prediction of the regimes of excited-state operation from the QDs is also included and experimentally verified. For the first time, the unsaturated absorption is identified as a key parameter that strongly influences the range of biasing conditions that produce stable mode-locked pulses. This dataset offers valuable insight into design of future MLL devices for maximum optical pulse quality over a large range of temperature and biasing conditions.