High-speed and transoceanic distance transmission with hybrid Raman-EDFA and coded modulation

We review recent high-capacity ultra-long haul experiments using hybrid Raman-EDFAs with optimized nonlinear performance and coded modulation with variable spectral efficiency. We discuss techniques that enabled record capacity (54Tb/s over 9,150km) and record capacity-distance product 534Pb/s*km (52.2Tb/s over 10,230km) demonstrations.