Wavelength Multicasting at 22-GBaud 16-QAM in a Silicon Nanowire Using Four-Wave Mixing

We demonstrate 1-to-6 wavelength multicasting of a 22-GBaud 16-QAM single polarization (6 × 88 Gb/s) signal based on four-wave mixing in a dispersion engineered silicon nanowire. All six multicast signals perform below the bit error rate forward error correction threshold of 3.8 × 10
^-3
, with a worst case power penalty of 8 dB. We compare our wavelength multicasting performance against the theoretical power transfer during a three-wave mixing process and show that the average power of degenerate idlers agrees with the predicted 6 dB difference with respect to that of nondegenerate idlers. When distinguishing the nonlinear conversion efficiency from the absolute idlers power at the output of the silicon nanowire, we also show the importance of the output grating coupler's loss and how it impacts the multicasting performance, in conjunction with the four-wave mixing efficiency.