Excitonic modeling of ground-state quenching dynamics in epitaxial quantum dot lasers on silicon

This work theoretically investigates ground-state (GS) quenching in dual-state lasing quantum dot (QD) lasers epitaxially grown on silicon. GS quenching, characterized by suppressiong of GS emission as bias current increases, results in a transition to excited-state (ES) emission, potentially degrading laser performance. Using an improved exciton model, incorporating a modified Boltzmann distribution, we model carrier dynamics and systematically examine the impact of optical losses on mitigating GS quenching. Our analysis reveals that the competition between GS and ES emissions intensifies at higher current densities, accelerating the transition to ES lasing. However, reducing optical losses by optimizing laser structural parameters effectively delays the onset of ES lasing to higher bias current densities, thereby stabilizing GS emission. Enhanced GS stability ensures more reliable laser operation, which is critical for applications in optical communications, photonic integrated circuits, and other systems requiring precise and stable light sources. These findings highlight the importance of controlling GS quenching to enhance the performance and versatility of QD lasers.