CALCULATING THE OPTICAL-PROPERTIES OF MULTIDIMENSIONAL HETEROSTRUCTURES - APPLICATION TO THE MODELING OF QUATERNARY QUANTUM-WELL LASERS

A method for calculating the electronic states and optical properties of multidimensional semiconductor quantum structures is described. The method is applicable to heterostructures with confinement in any numb er of dimensions: e.g. bulk, quantum wells, quantum wires and quantum dots. It is applied here to model bulk and multiquantum well (MQW) InG aAsP active layer quaternary lasers. The band parameters of the quater nary system required for the modeling are interpolated from the availa ble literature. We compare bulk versus MQW performance, the effects of compressive and tensile strain, room temperature versus high temperat ure operation and 1.3 versus 1.55 mu m wavelength operation. Our model shows that: compressive strain improves MQW laser performance. MQW la sers have higher amplification per carrier and higher differential gai n than bulk lasers, however, MQW performance is far from ideal because of occupation of non-lasing minibands. This results in higher carrier densities at threshold than in bulk lasers, and may nullify the advan tage of MQW lasers over bulk devices for high temperature operation.