High-Speed Resonant Cavity Enhanced Ge Photodetectors on Reflecting Si Substrates for 1550-nm Operation

摘要

We have designed and fabricated high-speed resonant cavity enhanced germanium (Ge) Schottky photodetectors on a silicon-on-insulator substrate. These back-illuminated detectors have demonstrated 3-dB bandwidths of more than 12 GHz at 3-V reverse bias and a peak quantum efficiency of 59% (R=0.73 A/W) at the resonant wavelength of ～1540 nm. Time domain measurements of our Ge photodetectors with diameters of up to 48 μm show transit-time limited impulse responses corresponding to bandwidths of at least 6.7 GHz, making these detectors compatible with 10-Gb/s data communication systems.