A Japanese team has today set a new world record for long-distance high-capacity transmission in optical fibre communications, which saw them achieve a data speed of 1.02Pbps (Petabits per second) over a distance of 1,808 km using a 19-core optical fibre cable with a standard 0.125mm cladding diameter.
The feat was achieved by a joint team of researchers from Sumitomo Electric Industries and the National Institute of Information and Communications Technology (NIICT) in Japan. Sumitomo was responsible for the design and manufacture of a coupled 19-core optical fibre that features a standard cladding diameter, achieving a reduction in optical fibre losses across multiple wavelength ranges (the C-band and the L-band) by optimizing the structure and arrangement of the cores.
Meanwhile, NICT was responsible for building a transmission system that maximizes the performance of the fibre, as well as developing and demonstrating an optical amplification relay function capable of simultaneously amplifying signals from all 19 cores.
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Faster data transmission speeds have of course been achieved before, using the same wavelength bands (C and L). The same team managed to hit a data rate of 1.7Pbps back in March 2023, but that was over a distance of just 63.7km, and the new achievement smashes that distance into the ground.
The new record pushes this technology closer to the realm of practical and economic viability for long-range optical communications, which could be used to upgrade existing links between countries (i.e. easily growing capacity as demand rises). But it’s worth noting that longer subsea fibres, such as those that run from Cornwall in England to New York in the USA (3,292 miles or 5298 km) would of course deliver slower, albeit still impressive, speeds.
Just to be clear. The World Record claim reflects that “capacity-distance product” (1.86 exabits per second – km) measurement when using a standard cladding diameter optical fibre, although given the pace of improvement in this field it probably won’t stand for long.
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19 cores is quite literally an odd number, unless they have some kind of monitoring running over the odd fibre out
1 centre. 6 round it. 12 round the 6.
There’s actually interaction between the cores, that’s the ‘coupled’ part, and they’re making use of it as part of the transmission so super precise on what’s going down which fibre. Probably have two of these cables in duplex next to each other rather than light running in different directions in different cores on the same cable. On a cable with coupled cores having light freshly leaving transmitter near light that’s arriving at receiver would be painful for crosstalk potential.