We report a resonant cavity Si photodiode grown by merged epitaxial lateral
overgrowth. At a reverse bias of 5 V, the dark current was 2.7 pA and the
bandwidth exceeded 34 GHz, The peak quantum efficiencies ranged from 42% at
704 nm to 31% at 836 nm. This is the highest speed reported for a Si p-i-n
photodiode and the highest bandwidth-efficiency product for any Si-based p
hotodetector.