High-Performance Wavelength Multicast With Beat Noise Suppression via Backward Raman Amplification in a Nonlinear Fiber

Fiber-based wavelength multicast offers an attractive solution for efficient and flexible wavelength resource management in future optical networks. Unfortunately, most multicast approaches suffer from inevitable pump-to-pump beatings, generating undesirable products that take up bandwidth resources and result in serious degradation of the output signal quality. In this paper, we propose and experimentally demonstrate the Raman-assisted wavelength multicasting technique. The system performance is assessed through a one-to-seven multicast configuration for 10-GBd QPSK signal. Up to ~16.8 dB power suppression has been achieved on the beating terms. Six newly generated replicas with Q factors all above the 7% forward error correction (FEC) threshold are obtained, despite their spectral overlap with the suppressed beating terms. Raman-assisted multicast further mitigates the performance penalty associated with signal power depletion, leading to a 0.8 dB Q factor improvement. Our proposed scheme enables more efficient utilization of the available spectrum in flexible bandwidth networks.