Abstract

Waveguide-integrated photodetectors provide the natural detection scheme following the on-chip processing of optical signals in semiconductor guides because they eliminate problems of alignment and the consequent tolerances and constraints on packaging. Both "end-fire" ^1,2 and "leaky" ^3-5 waveguide/detector configurations have been proposed and demonstrated. In the first, light is directed straight into the detector from the end of the guide, and in the second the optical field of the propagating mode leaks into the detector absorption region which lies adjacent to the guide. While end-fire structures have the potential for the ultimate highest speeds, they require regrowth of either the guide or detector which therefore lengthens and complicates the fabrication process. By contrast, "leaky" detectors may be formed from the same grown layer as the guide by sequential etching.

© 1989 Optical Society of America