Demonstration of a 90 Tb/s, 234.8 km, C+L band unrepeatered SSMF link with bidirectional Raman amplification

This work demonstrates the use of bidirectional Raman amplification to achieve an unrepeatered 234 km link using standard single mode fibers and with a capacity×distance product of 21.132 Pb/s·km. A throughput above 90 Tb/s is achieved with an 87 nm wavelength-division multiplexed signal carrying 424 PDM-64QAM signals at 24.5 GBaud across C and L bands. Transmission is supported using up to 12 Raman pumps per propagation direction, covering a wavelength range between 1410.8 nm and 1502.7 nm and with total power under 2.6 W.