INTEGRATED WAVEGUIDE PHOTODETECTOR APPARATUS WITH MATCHING PROPAGATION CONSTANTS AND RELATED COUPLING METHODS

摘要

High-speed optoelectronic devices having a waveguide densely integrated with and efficiently coupled to a photodetector are fabricated utilizing methods generally compatible with CMOS processing techniques. In various implementations, the waveguide consists essentially of single-crystal silicon and the photodetector contains, or consists essentially of, epitaxially grown germanium or a silicon-germanium alloy having a germanium concentration exceeding about 90%. Efficient evanescent coupling between components in the integrated apparatus is facilitated by forming the photodetector in lateral alignment with an optical waveguide and by matching propagation constants of the photodetector and the waveguide.