Ultra-Low Temperature Characterization of Fully-Integrated III-V Photodetectors for Quantum Networks

We present the first low temperature (5K-300K) characterization of scalable, waveguide-coupled III-V photodetectors integrated on silicon photonics platform. We also explore for the first time the excitation of traps in the heterojunction via both electrical and optical power. A reliability challenge is facet control in conventional Si <100> oriented wafers, so we also develop comparable photodetectors on SOI with <110> crystal orientation. This allows us to further scale the active region to $~λ{^3} /1550$ maintaining responsivity ~40% down to 5K and improveperformance variability by ~1000. This work shows the strong promise of this technology for future quantum optical links.