  We present waveguide integrated high-speed Si photodetector integrated with
silicon nitride (SiN) waveguide on SOI platform for short reach data
communication in 850 nm wavelength band. We demonstrate a waveguide couple Si
pin photodetector responsivity of 0.44 A/W at 25 V bias. The frequency response
of the photodetector is evaluated by coupling of a femtosecond laser source
through SiN grating coupler of the integrated photodetector. We estimate a 3dB
bandwidth of 14 GHz at 20 V bias, highest reported bandwidth for a waveguide
integrated Si photodetector. We also present detailed optoelectronic DC and AC
characterisation of the fabricated devices. The demonstrated integrated
photodetector could enable an integrated solution for scaling of short reach
data communication and connectivity.
