Silica-Core Single-Mode Fiber With Lowest Loss of 0.1397 dB/km

We achieved 0.1397 dB/km at 1566 nm and 0.1406 dB/km at 1550 nm on a silica-core single-mode fiber. Both of them were 2 mdB/km lower than the previously recorded low-loss fiber in 2017. The improvement of the transmission losses was realized by the reduction of Rayleigh scattering loss. We estimated the system performance using the fiber figure of merit theory, and it was shown that the number of repeaters could be reduced by 2% compared to the previously recorded low-loss fiber. This ultra-low loss fiber is expected to improve the submarine transmission system more cost- and power- efficient.