Waveguide integrated silicon avalanche photodetectors

We have fabricated silicon avalanche photodetectors integrated with silicon-on-insulator straight waveguides as well as ring resonator structures. The photodetectors comprise a p-i-n junction, with photogeneration mediated by the presence of deep-levels. For a 400 mu m straight waveguide detector we measure a responsivity of 4.4 A/W at 40 V, and an avalanche multiplication gain of 640. The detectors incorporated with a ring resonator, offer a high sensitivity, wavelength selective detector option suitable for very low power applications, with a responsivity of 20 A/W at 30 V.