Quantum capture area in layered quantum well structures

Carrier capture in quantum well structures defines high-speed properties of the lasers and amplifiers based on them. We introduce general definition of the capture area in low-dimensional heterostructures based on intersubband coupling coefficient. Spatial dependencies of intersubband coupling coefficient, which governs in fact capture rate, suggest on insufficiency of classical definition of capture area and necessity of quantum-mechanical computation of this value. Special case of layered quantum-well structures is considered. Computational results show necessity to take into account dependence of capture area on the temperature and device operating point.