Wavelength switching governed by carrier dynamics between two wells in an asymmetric dual-quantum-well laser

The barrier layers of usual multiple-quantum-well laser diodes (MQW LDs) are designed such that the barriers are low and/or thin enough so that the injected carriers distribute uniformly across the wells. In contrast, asymmetric dual-quantum-well (ADQW) LDs are composed of two different wells separated by a barrier layer which is high and/or thick so that the quasi-thermal equilibrium between the two wells is violated, which results in a nonuniform carrier distribution.1–3