NTT Four-Core Optical Fiber Quadruples Cable Capacity
Japan’s Nippon Telegraph and Telephone has developed a four-core multicore optical fiber designed to carry four times more data than conventional single-core fiber while keeping the same external diameter.
NTT says the unchanged size is critical because it allows the new fiber to remain compatible with existing submarine cable systems, land-based connections and telecom equipment racks. The company has positioned the technology as a way to expand network capacity without requiring a full redesign of cable infrastructure.
Just as four-core optical fiber expands network capacity, innovations in optical communication are also delivering remarkable speed, such as how Wireless Optical Communication Reaches 362 Gbps Speed Indoors for efficient high-speed indoor connectivity.
How the technology works
Instead of one optical core, the new fiber contains four separate cores inside the same glass cladding. Data is transmitted through spatial multiplexing, allowing four independent optical paths to operate within a single fiber.
For submarine systems, the potential capacity gain is significant. NTT says conventional submarine cable designs can include up to 48 fibers; using four-core multicore fiber would raise that to 192 cores in the same cable structure.
Why it matters
NTT has also prepared supporting components for deployment, including submarine joint boxes, factory joint boxes and terminal racks for connecting multicore fiber systems with conventional single-core infrastructure. These additions are intended to reduce the complexity of introducing the technology into real networks.
The development comes as telecom operators face rising traffic from 5G, artificial intelligence and cloud services. If deployed as planned, the technology could help increase backbone and submarine network capacity without laying much larger cables.
Deployment timeline
Commercial deployment is expected around 2029. NTT has presented the system as part of its broader work on high-capacity optical transmission infrastructure.
Source: Tomshardware
