A startup just raised $22 million to bet that data centers need a different kind of glass in their cables.
Relativity Networks closed the round to commercialize hollow-core fiber, a technology that mostly stays in research labs and rarely reaches live networks. Unlike standard fiber, which sends light through solid glass, hollow-core fiber routes it through air, cutting the drag that slows signals down. The company says that translates into data moving 30% faster than it does over conventional fiber. The funding will presumably go toward manufacturing and pitching the technology to the data center operators who would need to install it.
Data centers already spend heavily to shave milliseconds off transfers between racks, particularly for AI training clusters where expensive GPUs sit idle waiting on data. A 30% speed gain, if it holds outside a lab, is the kind of number that could matter more to hyperscalers than another chip refresh. Hollow-core fiber has circulated in research circles for years without catching on commercially, which suggests the obstacle has always been manufacturing cost and scale, not the underlying physics.
Whether $22 million buys enough manufacturing muscle to succeed where bigger telecom incumbents haven't is the open question.