YOFC hollow-core fiber hits 51.3 Tb/s over 128 miles unrepeatered; AI-era backbone milestone

China's Yangtze Optical Fiber and Cable (YOFC) announced on June 16 a world-record field trial achieving 51.3 Tb/s transmission over 206.5 km (128 miles) of hollow-core fiber without signal repeaters. The trial, conducted with China Telecom and equipment maker Dekoli, used only standard erbium-doped fiber amplifiers and delivered 1.2 Tb/s per wavelength—the first field-scale demonstration at this capacity and distance combined.

Hollow-core fiber guides light through air instead of solid glass, delivering roughly 31% lower latency, 47% faster propagation speed, and lower nonlinear distortion than conventional fiber. YOFC achieved this benchmark through two innovations: a self-developed per-wavelength power and rate allocation scheme to minimize gas-absorption losses in the air core, and a dual-gain-unit amplifier architecture delivering 33.5 dBm output while maintaining flat gain across the band.

The 206.5 km unrepeatered span eliminates intermediate amplification stations, reducing operational complexity and cost for long-haul backbones. This matters to data center architects because it directly addresses the network bottleneck that AI scale-out creates: the fiber linking GPU clusters inside and between facilities is increasingly the limiting factor in training and inference throughput. Lower latency is also critical for financial trading, cloud compute, and inference workloads where milliseconds compound.

Western players—Microsoft (via Lumenisity), AWS, Meta, and Corning—have already begun scaling HCF deployments, with Microsoft claiming 15,000 km targeted by end-2026. YOFC's field trial closes the gap on commercial readiness outside the Western supply chain and signals that hollow-core fiber adoption is moving from lab milestones to live network deployments. Watch whether Chinese carriers and hyperscalers integrate HCF into backbone and inter-cluster routes faster than Western players.