Sumitomo Electric and NICT Develop the World’s First 19-core Optical Fiber

Sumitomo Electric Industries, Ltd. and the National Institute of Information and Communications Technology (NICT) have developed a randomly coupled multi-core optical fiber with 19 cores, the world’s largest number of cores for a multi-core optical fiber*1 with a standard outer diameter*2 (0.125 mm), and succeeded in transmitting 1.7 petabits per second over 63.5 km.

Role

Sumitomo Electric: Designed and manufactured of randomly coupled 19-core optical fibers with a standard outer diameter.

To date, Sumitomo Electric has developed a randomly coupled 4-core optical fiber and a randomly coupled 7-core optical fiber with a standard outer diameter suitable for long-distance large-capacity transmission. This time, Sumitomo Electric has realized a randomly coupled multi-core optical fiber with 19 cores, the world’s largest number of cores for a standard outer diameter optical fiber, by optimizing the structure and arrangement of cores.

NICT: Constructed a transmission system to demonstrate the maximum capability of this fiber, and conducted a transmission experiment.

The transmission performance evaluation of randomly coupled multi-core optical fibers is not easy due to signal interference. NICT constructed an optical transmission system that can simultaneously receive 19-core signals at a high symbol rate and evaluated the maximum fiber transmission capacity through wavelength-division-multiplexed coherent transmission experiment.

Demonstration
Using commercial wavelength bands (C- and L-bands)*３ and polarization-multiplexed 64 QAM signals,*４ a total transmission capacity of 1.7 petabits per second over a transmission distance of 63.5 km has been demonstrated.

Demonstration Results
As a result of this demonstration, the companies have not only set a world record for the transmission capacity of standard-outer-diameter multi-core optical fibers, but also a world record for the longest distance in a petabit-per-second class standard-outer-diameter multi-core optical fiber transmission demonstration. These achievements also show the possibility that even if the number of cores in a randomly coupled multi-core optical fiber is increased to 19, the load (power consumption) of the MIMO digital signal processing*5 required for 10,000 km-class transmission for transoceanic communication and other similar applications can be greatly reduced compared to multi-mode optical fiber transmission,*6 demonstrating the scalability of the number of cores in randomly coupled multi-core optical fibers. Randomly coupled multi-core optical fibers and their transmission technology are expected to become a key technology that paves the way for increasing the capacity of long-distance optical communication networks.

The paper on the results of this demonstration was highly evaluated at the 46th International Conference on Optical Fiber Communications (OFC 2023), being selected as the best hot topic paper (Post Deadline Paper) and presented on March 9, 2023.