Optical-Time-Division Demultiplexing of 172 Gb/s to 43 Gb/s in a-Si:H Waveguides

We demonstrate optical-time-division demultiplexing of 172-43 Gb/s based on degenerate four-wave mixing in a 17-mm-long hydrogenated amorphous silicon (a-Si:H) wire waveguide. The a-Si:H wire waveguide has a record-low propagation loss of 1.0 dB/cm and a low two-photon-absorption loss of 0.2 cm/GW, and the nonlinear figure of merit is estimated to be 0.97, which is more than twice as effective as conventional crystalline silicon wire waveguides. We achieved successful error-free demultiplexing with an ON/OFF conversion efficiency of -10 dB and a power penalty of only 1.1 dB at a bit error rate of 10^-9. No optical damage to the a-Si:H waveguide was observed even after a continuous pump injection at an average power of several tens of mW for a couple of hours.