Monolithic optoelectronic TWE-component structure

Monolithic optoelectronic TWE-component structure for high frequencies and low optical insertion loss. A monolithic optoelectronic device has a spot-size converter optically connected to a waveguide. The overclad (58) extending over the core (54) of the waveguide is thinner and more highly doped than the overclad of the spot-size converter. This structure can be made by applying a process of selective etching and enhanced regrowth to create selective regions of the overclad (58) of different thickness or doping.