- Microsoft wants to ramp its hollow core fiber (HCF) deployments to better support AI workloads
- The hyperscaler tapped both Corning and German vendor Heraeus to produce HCF
- HCF could let light travel faster than on single mode fiber
With AI and cloud workloads demanding higher speeds and low latency, Microsoft wants to ensure it has enough hollow core fiber (HCF) to meet the task.
The tech giant struck agreements with Corning and Heraeus Covantics to ramp its global HCF deployments. It aims to create a “multinational production supply chain to scale next generation fiber production,” Microsoft said in a blog.
Unlike traditional single mode fiber, HCF guides light through a hollow, air-filled core rather than through solid glass. Proponents of the technology believe that because light should travel faster through air than glass, HCF could bring higher bandwidth rates for latency-sensitive applications.
For Corning, this appears to be the first time the vendor has publicly announced that it will manufacture HCF. Its optical fiber has already garnered attention from the likes of Lumen, which reserved 10% of Corning’s global fiber capacity to build out its enterprise fiber backbone.
Corning will produce the HCF in its North Carolina factories. Heraeus, a German company that provides quartz and fused silica products for the semiconductor, photonics and telecommunications industries, will make the fiber in fabs across both Europe and the U.S.
State of hollow core fiber deployment
Microsoft has been at the HCF game for some time. The company began deployments in late 2022 after acquiring Lumenisity, an HCF supplier that came up with a way to reduce the technology’s data transmission loss.
It’s an endeavor Microsoft has worked on as well. Microsoft, along with researchers from the U.K.’s University of Southampton, recently announced they designed an HCF with a loss of less than 0.1 decibels per kilometer.
Light in this new fiber can travel approximately 33 kilometers before seeing a power reduction, the researchers noted, whereas standard telecom fibers (that typically have a signal loss of around 0.2 dB/km) can only reach 15 kilometers before experiencing the same.
While Microsoft is currently a big player in the HCF field, others are also dabbling in the technology. Operators like BT and Comcast have trialed HCF in their networks for use cases ranging from quantum key distribution (QKD) to financial services. In China, optical vendor YOFC teamed up with China Mobile last year to launch what they claimed is the world’s first 800G hollow-core fiber network.
HCF shortcomings
Despite the ongoing testing and recent improvements in signal loss, it could still take a while before we see wider adoption of HCF.
Derrick Lathrop, technical program manager of longhaul network planning at Google, commented on LinkedIn that splicing HFC requires “highly specialized equipment” that isn’t yet widely available. Furthermore, he said operators currently don’t have trained outside plant (OSP) teams specifically for HCF, which also has lower crush and pull tolerance than single-mode fiber.
Lathrop added that present day Optical Time-Domain Reflectometers (OTDRs), the devices used to test and maintain fiber networks, “do not have the ability to detect moisture, dust, or breakage w/in HCF - all items that will impair transmission."