All-silicon and epitaxially grown III-V-on-silicon photodetectors for on-chip optical interconnection applications

In this paper we review our recent progress in two complementary approaches to photodetectors on silicon photonic chips for on-chip optical interconnection applications, namely epitaxially grown III-V-on-silicon and all-silicon microcavity-enhanced photodetectors, both for the 1550nm wavelengths. On the epitaxially grown III-V-on-silicon photodetectors front, we have demonstrated both normal-incidence and waveguide-butt-coupled p-i-n photodetectors. We simulate the silicon waveguide butt-coupling to the InGaAs absorption region and estimate the absorption efficiency using a three-dimensional finite-difference time-domain method. We optimize the InGaAs absorption region in order to attain a bandwidth of 46 GHz. We also report our latest experimental demonstration of all-silicon microresonator-enhanced linear-absorption photodetectors using defect-state absorption in pn-diode-integrated microresonators. Our initial experiments reveal the measured bandwidths to be exceeding 10 GHz.