Self-aligned index-guided multiple quantum well laser by sulphur diffusion-induced disordering

A simple self-aligned fabrication process for sulphur-diffusion disordered AlGaAs/GaAs multiple quantum well (MQW) lasers is described that produces refractive index guiding. However, the gradual profile of sulphur diffusion causes a separation between the disordered/nondisordered interface and the pn junction which leads to a large lateral optical loss of the index-guided mode.