SEMICONDUCTOR DEVICE

摘要

A semiconductor optical device, for example a laser, has a composite optical waveguide comprising a tapered, MQW active waveguide (1), in optical contact with a substantially planar, passive waveguide (2). The fundamental optical mode supported by the composite waveguide varies along the length of the composite waveguide so that, in a laser, the laser mode is enlarged and is a better match to single mode optical fibre. A method for making such semiconductor optical devices is also disclosed.