Structural dependence of carrier capture time in semiconductor quantum-well lasers

Carrier capture for InGaPA-based and InGaAlAs-based multiple quantum-well structures for the 1.55 μm wavelength regime was investigated. The capture time and dynamics were found to be governed by transitions between quantum states that were delocalized throughout the whole structure. It was found that the concept of a unique capture time was often not appropriate, since this time was not a constant that is characteristicc for a given quantum well. It was shown that the capture can be made faster by using structures with a larger ratio of well- to barrier-material.