Relativity Networks secures $22 million to deploy faster hollow-core fiber in data centers

Relativity Networks announced a $22 million financing round using SAFE notes, with participation from Rhapsody Venture Partners, Bell Ventures Inc. and Faster Than Glass LLC among others. In addition, the company secured a $40 million follow-on order from a leading hyperscaler that declined to be named. The startup’s product is hollow-core fiber, a technology that moves light through an empty core rather than glass, delivering about a 30 % latency reduction—cutting travel time per kilometer from roughly five microseconds to three and a half.

CEO Jason Eisenholz explained that as AI systems grow, the physical distance between GPUs across sprawling data-center campuses becomes a bottleneck, and the faster fiber can mitigate that constraint. He envisions multi-campus deployments operating as a single synchronized machine, allowing developers to extend the geographic footprint of compute without sacrificing performance. This advancement could reshape the economics and layout of future data-center construction as the industry moves into a third era focused on geographic optimization.