Flexible Optical Cross-Connect Structures Supporting WDM Multicast With Multiple Pumps for Multiple Channels

We not only propose three flexible optical cross-connect (OXC) structures, with the ability of wavelength-division multiplexing (WDM) multicast, but also experimentally demonstrate two WDM multicast schemes based on four-wave mixing in a semiconductor optical amplifier (SOA). One-to-ten WDM multicast of 25-Gb/s QPSK signals is achieved with three pumps, and the power penalties for all signals are less than 1.7 dB. For the first time, dual-channel WDM multicasts are simultaneously realized with only two pumps. One-to-six multicast for one input with the largest power penalty of 1.28 dB is obtained, whereas one-to-three multicast for the other input with the power penalty of 1.27 dB is also realized. The demonstrated schemes can be applied to the proposed OXC structures, according to the different requirements. The effect of bias current on conversion efficiency and optical signal-to-noise ratio is also discussed, and the optimal value is given.