In a landmark achievement for the telecommunications industry, a research team supported by Microsoft’s Lumenisity has developed a new generation of hollow-core optical fibers, reaching the lowest signal attenuation ever recorded. The results, published on September 1 in Nature Photonics, are being hailed as one of the most significant advancements in waveguide technology in the past 40 years.
What Is Hollow-Core Fiber?
Unlike conventional solid-core fibers made from silica glass, hollow-core fibers guide light through an air-filled central channel, surrounded by ultra-thin concentric glass tubes. These structures act as microscopic mirrors, confining light within the hollow core while suppressing higher-order modes.
Because air absorbs and scatters light far less than glass, hollow-core fibers reduce attenuation dramatically, enabling light to travel longer distances with minimal loss. This marks a breakthrough that overcomes the physical limits of traditional fiber optics.
The Breakthrough
Microsoft’s team achieved this milestone using a dual nested anti-resonant nodeless fiber (DNANF) structure, which relies on photonic bandgap effects to trap light effectively within the air core.
Key performance highlights include:
Attenuation of 0.091 dB/km at 1550 nm, surpassing the theoretical limit of 0.14 dB/km for conventional silica fibers.
Low loss (<0.2 dB/km) over a 66 THz bandwidth, far wider than traditional fibers.
Seven times lower chromatic dispersion, simplifying transceiver design and reducing energy consumption in networks.
Up to 45% faster data transmission speeds, opening new frontiers in latency-sensitive applications.
From Lab to Industry
This is not just theory—Microsoft has already begun deploying hollow-core fiber technology in real-world networks. Since acquiring Lumenisity in 2022, Microsoft has invested heavily in advancing industrial-scale production. By late 2024, the company announced plans to deploy 15,000 km of hollow-core fiber across its Azure global network, supporting AI-driven workloads and high-performance computing demands.
Meanwhile, global telecom leaders are also accelerating adoption. In China, operators like China Mobile and China Telecom have launched commercial pilot projects, achieving record-low attenuation levels (as low as 0.065 dB/km). Analysts predict rapid cost reductions and broader applications across finance, data centers, submarine cables, and even fields like quantum communication and medical lasers.
Challenges Ahead
Despite the excitement, challenges remain. Scaling production of hollow-core fiber is complex, and industry standards are still evolving. Integration with existing solid-core infrastructure also requires innovative connection solutions. However, with major players advancing the technology, widespread commercialization appears increasingly realistic.
Conclusion
The breakthrough in hollow-core fiber represents more than just incremental progress—it is a transformational leap for optical communication, paving the way for faster, more efficient, and more sustainable global connectivity. As AI, cloud computing, and data-intensive industries continue to grow, hollow-core fiber may soon become the backbone of next-generation networks.
