8-Channel SiO2/Si3N4/Si/Ge CWDM Receiver

We demonstrate a monolithic 8-channel CWDM receiver. It has a spot-size converter in SiO2 and Si3 N4, an arrayed-waveguide grating (AWG) in Si3N4, fanout waveguides in Si, and photodetectors in Ge. By varying the waveguide widths in the AWG, polarization independence is achieved. The responsivity from fiber to photodiode for the best channel is higher than 0.34 A/W over all polarizations. We demonstrate -20.5-dBm sensitivity at 10-12 bit-error rate at 2.5 Gb/s for one of the channels using a commercial small-form-factor pluggable (SFP) transceiver as a transmitter.