Innovative Fiber Technology Achieves Unprecedented Transmission Capacity
Yangtze Optical Fiber and Cable Joint Stock Limited Company (YOFC) has set a new standard in optical communications with the successful completion of a field trial utilizing hollow-core fiber (HCF) wavelength-division multiplexing (WDM). Announced on June 16, the trial, in collaboration with China Telecom and Dekoli, showcased a staggering transmission capacity of 51.3 Tb/s over a distance of approximately 128 miles (206.5 km) without the need for signal regeneration.
This achievement is significant not just because of its capacity, but also due to the combination of distance and the innovative use of erbium-doped fiber amplifiers (EDFA). Previous demonstrations had shown capabilities of 1.2 Tb/s over a single wavelength but were limited to much shorter spans. For context, China Telecom's past success in July 2024 was confined to a mere 20 kilometers.
While other researchers have extended unrepeatered HCF spans beyond 300 kilometers, they have not matched this capacity level. YOFC claims that achieving 1.2 Tb/s over more than 200 kilometers in a commercial setting represents a notable advancement, particularly because it relies solely on traditional EDFA amplification instead of remote-pumped boosters.
Hollow-core fiber presents a compelling alternative to conventional optical fibers. Instead of guiding light through a solid glass core, HCF utilizes an air-filled channel, which enables superior performance. Light travels faster in air — approximately 1.5 times quicker than in glass — which reduces latency. Additionally, the air core minimizes some nonlinear distortions and dispersion typically associated with silica-based fibers. YOFC had previously reported significant improvements in latency and transmission speed with its HCF technology compared to traditional fibers.
Historically, the challenge for hollow-core fiber has been the higher attenuation rates, which have restricted operational ranges. However, the recent trial has indicated significant progress in overcoming these limitations, showcasing an unrepeatered distance that has been long sought after in the industry.
Innovative Techniques Drive Success
One of the key developments in this successful trial stemmed from enhancements at both the system and hardware levels. The system leverage a unique optimization strategy for wavelength rates and channel power allocations. By tailoring the data rate and power for each wavelength based on link conditions, the system effectively reduces capacity losses due to gas absorption characteristics unique to air guidance.
On the hardware side, the research team advanced the capability of their amplifier design, employing a cascaded dual-gain-unit architecture. This setup achieved a peak output of approximately 33.5 dBm (about 2.24 W), allowing for efficient amplification across diverse operational bands without needing remote-pumped systems. To mitigate potential risks associated with high power levels in live links, safeguards were introduced, including real-time power anomaly detection and automatic system shutdown protocols.
Implications for AI and Data Center Networking
The implications of YOFC’s achievement are particularly pertinent as demands for data capacity surge, especially in artificial intelligence (AI) environments. With hyperscale cloud providers expanding their GPU clusters, the networking infrastructure connecting these systems has become a critical bottleneck. The enhanced performance and lower latency of HCF allow operators to position data centers further away from power-sensitive hubs without sacrificing speed, accommodating the substantial traffic generated by AI processes.
Moreover, the growing interest in leveraging HCF technology isn't limited to China. Major players in the West, like Microsoft and AWS, are making significant investments in hollow-core fiber development to enhance their data transmission capabilities. Microsoft’s acquisition of Lumenisity accelerated its ventures into HCF, while AWS claims its own fiber solution delivers a notable latency improvement over traditional options. Companies such as Corning are forging agreements with tech giants like Meta and Nvidia, signaling a broad interest in scaling HCF technology for future networking demands.
YOFC's successful trial not only sets a new benchmark in fiber optic performance but potentially paves the way for wider adoption of hollow-core fiber technology, even as the global supply chain adapts to these advancements.
