Led by Japan’s NICT and Sumitomo Electric, a groundbreaking milestone has been achieved in telecommunications by transmitting data over the longest and fastest distance ever recorded with standard optical fiber.
The race to expand communication infrastructure capabilities has made a historic leap. The National Institute of Information and Communications Technology (NICT) of Japan, in collaboration with Sumitomo Electric Industries and other European research centers, managed to transmit 1.02 petabits per second (Pbps) over 1,808 kilometers of fiber optic cable—a new world record that redefines long-distance connectivity limits.
This achievement, announced as a postdeadline paper at the 48th Optical Fiber Communications Conference (OFC 2025) in San Francisco, was made possible using a new 19-core fiber with a standard cladding diameter of 0.125 mm, allowing integration with existing infrastructure.
A Historic Achievement
Until now, petabit-per-second transmissions were limited to shorter distances. Achieving this capacity over nearly 2,000 km is a technological marvel, combining extremely high data density, low signal loss, and an optical amplification system specifically developed for this multicore fiber.
According to NICT, the product of capacity and distance reached 1.86 exabits per second-kilometer—the highest value ever recorded with standard-diameter optical fibers.
This result not only sets a record but also paves the way for ultra-fast, long-range optical networks capable of handling the exponential growth in data demand driven by artificial intelligence, cloud computing, 8K video, and the metaverse.
Advanced Technology
The fiber used in the experiment features 19 coupled cores, each transmitting data simultaneously across 180 wavelengths in the C and L bands of the optical spectrum. Each channel was modulated using 16QAM (Quadrature Amplitude Modulation), a technique that encodes 4 bits per symbol by leveraging light amplitude and phase.
The system included 19 recirculating transmission loops of 86.1 km each, through which the signal was circulated 21 times to reach the total distance. Digital MIMO (Multiple Input, Multiple Output) processing was applied after transmission to separate signals from the different cores and correct interference.
The combined data rate exceeded 1,000,000 gigabits per second—equivalent to transmitting the monthly broadband traffic of all fixed-line users in Japan in less than four seconds.
Implications for the Future
As society moves toward a post-5G era, where massive interconnection of devices, autonomous vehicles, smart cities, and extended reality services demand unprecedented bandwidths, a revolution in network infrastructure is necessary.
This breakthrough by NICT and its partners marks a crucial step toward optical networks that can multiply capacity without increasing physical space or energy costs—key factors in sustainable technology development.
“ ahora el desafío es mejorar la eficiencia energética de los amplificadores ópticos, optimizar el procesamiento MIMO y avanzar hacia aplicaciones comerciales viables”, explicaron los responsables del proyecto. En otras palabras, transformar un récord de laboratorio en una solución de mercado.
International Collaboration
In addition to NICT and Sumitomo Electric, researchers from Eindhoven University of Technology (Netherlands), Politecnico di Milano (Italy), and the University of Stuttgart (Germany) participated in this project. This collaboration underscores how international scientific research continues to drive innovation in telecommunications.
As the team stated, “we have demonstrated that it’s possible to combine a compact design compatible with existing infrastructure with extreme performance. This is not only a technical achievement but a vision for the future global network.”
A Record-Breaking Connection
| Parameter | Value |
|—————————|—————————|
| Total capacity | 1.02 petabits per second |
| Total distance | 1,808 km |
| Fiber cores | 19 |
| Wavelengths used | 180 (C and L bands) |
| Modulation | 16QAM |
| Capacity-distance product | 1.86 exabits/sec·km |
| Cladding diameter | 0.125 mm (standard) |
| Presentation event | OFC 2025 (San Francisco, USA) |
Conclusion
As the world faces the challenge of scaling connectivity without compromising sustainability or interoperability, this record signifies a turning point. With smarter fibers, more efficient amplifiers, and advanced processing, the future of the internet could be nearer—and faster—than we imagined.
Source: National Institute of Information and Communications Technology (NICT), Japan