Patent ID: 8871554

Claim:
A method for fabricating an electro-absorptive modulator or detector, said method comprising: forming a doped semiconductor layer on a substrate; depositing a first cladding layer on said doped semiconductor layer; depositing and patterning a waveguide layer to form a plurality of waveguides; depositing a second cladding layer on top of said waveguide layer; etching a trench through said second cladding layer, said waveguide layer, and said first cladding layer to expose said doped semiconductor layer; depositing a film spacer layer on top of said second cladding layer to cover said trench; etching said film spacer layer to form respective sidewalls within said trench; and forming an electro-absorptive modulator within said trench such that said electro-absorptive modulator is butt-coupled to said waveguides via said sidewalls.