A major Japanese telecommunications company, Nippon Telegraph and Telephone (NTT), has announced the development of a four-core multicore optical fiber (MCF) that can deliver four times the data capacity of conventional fiber while maintaining the same thickness and diameter.<\/p>\n\n\n\n
The company emphasized that keeping the cable\u2019s cross-section unchanged is critical for compatibility with existing infrastructure. This includes not only cable-laying vessels but also terrestrial interconnect systems and terminal racks, allowing the new fiber to integrate without requiring major changes.<\/p>\n\n\n\n
Unlike traditional single-core optical fibers, the new MCF contains four separate cores surrounded by glass cladding. Using spatial multiplexing, signals can travel through each core independently.<\/p>\n\n\n\n
This allows a single fiber to carry four separate optical paths at the same time. In undersea cables that typically bundle up to 48 fibers, this technology increases capacity significantly, enabling a single cable to support up to 192 cores.<\/p>\n\n\n\n
To support deployment, NTT has also developed several technical components designed for easy integration. These include a submarine joint box that connects conventional terrestrial fiber cables to the four-core undersea cable, and an MCF cable terminal that links the multicore fiber to transmission equipment designed for single-core systems.<\/p>\n\n\n\n
Additionally, a factory joint box allows two MCF cables to be connected on the seabed.<\/p>\n\n\n\n
NTT expects the new multicore fiber technology to be ready for deployment by 2029. The innovation could help telecom companies increase network capacity while reducing costs and deployment time, as it eliminates the need for a complete overhaul of existing systems.<\/p>\n\n\n\n