There is disclosed an improved method of manufacturing an optical device using an impurity induced Quantum Well Intermixing (QWI) process. Reported QWI methods, and particularly Impurity Free Vacancy Diffusion (IFVD) methods, suffer from a number of disadvantages, eg the temperature at which Gallium Arsenide (GaAs) ...

A method for fabricating a semiconductor device in a semiconductor structure, provides enhanced quantum well intermixing in desired regions of the device by forming a first, relatively high quality, epitaxial layer on a substrate, the high quality layer including a quantum well; forming a second, relatively lower qu...

There is disclosed an improved method of manufacturing an optical device using an impurity induced Quantum Well Intermixing (QWI) process. Reported QWI methods, particularly Impurity Free Vacancy Diffusion (IFVD) methods, suffer from a number of disadvantages, e.g. the temperature at which Gallium Arsenide (GaAs) ou...

A semiconductor laser device incorporates a beam control layer (42, 41) for reducing far field and beam divergence. Within the beam control layer, a physical property of the semiconductor material varies as a function of depth through, the beam control layer, by provision of a first sub-layer (42) in which the prope...