All-optical three-input simultaneous multicasted quaternary addition/subtraction using non-degenerate FWM in a silicon waveguide and 20 Gibt/s QPSK signal

By exploiting multiple non-degenerate four-wave mixing (FWM) and quadrature phase-shift keying (QPSK) signals, we experimentally demonstrate three-input (A, B, C) simultaneous multicasted quaternary addition/subtraction (A+C-B, A+B-C, B+C-A) at 20 Gbit/s based on a silicon waveguide. Alignment tolerance of three input signals is also evaluated in the experiment.