As global data flows surge toward oceans at unprecedented rates, can existing submarine cables continue to bear this exponentially growing information demand? The outlook appears challenging. However, Yangtze Optical Fibre and Cable (YOFC) has collaborated with China's top research institutions to develop a revolutionary solution — successfully deploying the world's first seven-core fibre submarine test cable, setting a new world record for field-installed distance of space-division multiplexing submarine cables and laying solid groundwork for Pbit/s-class ultra-high-speed transoceanic communication links.
Breaking Capacity Barriers, Redefining Submarine Networks
Amid the digital economy boom, transoceanic data transmission demands are growing exponentially, exposing the capacity limitations of traditional single-mode submarine cables. YOFC has identified this industry challenge and strategically invested in multi-core fibre technology, offering a promising solution for next-generation submarine communications.
The seven-core fibre's fundamental advantage lies in its innovative design, integrating multiple independent cores within a single fibre to enable parallel signal transmission through space-division multiplexing. This approach multiplies transmission bandwidth without increasing cable diameter, overcoming traditional capacity constraints. Furthermore, the technology significantly increases the number of amplifier-ready cores, improving deployment efficiency while reducing long-term operational costs — fundamentally addressing scalability issues plaguing conventional submarine cables.
YOFC's collaboration with Sun Yat-sen University, Southern Marine Science and Engineering Laboratory, Jinan University, Hangzhou Liutong Photonics Technology, and China Mobile Guangdong has resulted in the successful deployment of this experimental cable between Guishan Island and Outer Lingding Island in the Greater Bay Area. This achievement represents not just a technical breakthrough but a profound exploration of future submarine communication development. The project's findings were published as a PDP paper at the 2025 OECC international conference, drawing significant industry attention and signaling imminent transformation in submarine communications.
YOFC's Seven-Core Fibre: Unchanged Dimensions, Transformed Performance
As a global leader in optical fibre manufacturing, YOFC leveraged its technical expertise to develop the high-performance seven-core fibre for this project. The innovation achieves "unchanged dimensions with enhanced performance," providing crucial support for submarine communication capacity upgrades and performance optimization. Three key technical breakthroughs stand out:
- Dimensional Compatibility: The seven-core fibre maintains a 250-micron coating diameter identical to conventional single-mode fibres, eliminating the need for extensive modifications to existing cable production, deployment, and terminal equipment. This design significantly reduces implementation costs while multiplying communication channels within the same cable space.
- Communication Capacity: Unlike single-mode fibres' single-channel transmission, the seven-core fibre integrates seven independent transmission channels, multiplying data transfer capacity. This advancement proves critical for addressing growing marine communication demands, alleviating bandwidth pressure on existing networks while providing core technology for future marine information highways.
- Transmission Performance: The seven-core fibre demonstrates exceptional stability, meeting rigorous submarine cable standards. Its trench-assisted core design ensures each core's bending loss complies with G.657 standards while minimizing inter-core crosstalk, guaranteeing stable and reliable signal transmission.
Complete Solution with Key Components
Complementing the seven-core fibre, the seven-core fan-in/fan-out device plays a vital role in enabling efficient adaptation between the new fibre and existing communication systems. This critical component facilitates experimental validation of ultra-high-density space-division multiplexing submarine cable transmission systems, demonstrating YOFC's capability to deliver complete submarine communication solutions beyond fibre manufacturing.
Space-Division Multiplexing: Shaping the Future of Submarine Communications
YOFC's successful deployment of the world's first seven-core submarine cable marks a significant breakthrough in space-division multiplexing technology for China. The innovation effectively addresses traditional submarine cables' capacity limitations and high maintenance costs while proposing new approaches for building more efficient and economical submarine networks. As space-division multiplexing technology matures, it will optimize global information interconnectivity, strengthen submarine communication infrastructure, and position China's advanced optical communication technologies on the world stage.
Through its innovative spirit and technical capabilities, YOFC is leading the future development of submarine communication technologies. Multi-core fibre solutions are poised to become the mainstream choice for constructing Pbit/s-class ultra-high-speed transoceanic links, establishing robust "submarine expressways" for global connectivity and contributing to a more integrated, efficient, and interconnected world.