Abstract: An alignment and fixing apparatus for positioning and securing an optical fibre in alignment with an optical source, in which the optical fibre is coupled, at two longitudinally separated points along the fibre, to respective ones of a pair of cantilever arms. Lateral movement of one of the cantilever arms induces a smaller lateral movement of the other cantilever arm, thereby enabling precision lateral displacement of an end of the fibre proximal to the optical source.

Abstract: A semiconductor laser device incorporates a beam control layer 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 in which the property varies gradually from a first level to a second level, and a second sub-layer in which the property varies from said second level to a third level. In the preferred arrangement, the conduction band edge of the semiconductor has a V-shaped profile through the beam control layer.

Abstract: A method of performing quantum well intermixing in a semiconductor device structure uses a sacrificial part of a cap layer, that is removed after QWI processing, to restore the cap surface to a condition in which high performance contacts are still possible.