Forward-looking: Fiber optic cables are the backbone of modern internet-based communications, moving zettabytes of data per year from every corner of the digital world. Fiber optic technology must therefore evolve at an accelerated pace, as data traffic demands are only increasing, never subsiding.

An international team of researchers from the Japanese National Institute of Information and Communications Technology (NICT), Eindhoven University of Technology, and the University of L'Aquila has achieved a new, unprecedented transmission capacity over a single fiber optic cable. The scientists were able to transfer 22.9 petabits per second (or 22,900 terabits/s), combining different technologies to double the previous world record of 10.66 petabits per second.

Fiber optic cable must cope with the ever-increasing data traffic demands coming from companies and internet users, the researchers explained, employing advanced data transfer solutions such as multiplexing technologies using space and wavelength. The former uses "advanced" optical fibers containing multiple optical paths (or channels) within a common cladding, NICT said, while the latter enhances the total transmission capacity by increasing bandwidth with many independent Wavelength Division Multiplexed (WDM) data channels.

The Japanese researchers were able to realize Space Division Multiplexing (SDM) with over 100 spatial channels, building a 38-core, three-mode cable where each core can transfer between 0.3 and 0.7 Pb/s. The total transmission capacity of the new fiber optic cable was 22.9 Pb/s, but the result also includes an overhead for additional error correction capabilities.

With better-optimized coding, transfer rate levels of up to 24.7 Pb/s could be achieved. That's more than 1,000 times the data rate available through currently deployed optical fiber communication systems, the researchers explained.

Before entering the market, the new transfer technology would need a further improvement to the telecommunication infrastructure dealing with fiber optic tech. Ultra-large-capacity fibers will be required for future internet comms, NICT said, as the data traffic demand is expected to increase by three orders of magnitude, or 1,000 times.

The new international study provides the first practical, successful demonstration for the combination of multi-band WDM and SDM employing a multicore multimode fiber. This kind of technology will be a key advancement for future fiber optic-based networks. The paper was accepted as a post-deadline presentation during the 49th European Conference on Optical Communication recently held in Glasgow.