China Just Sent Data Through Air Instead of Glass — 51.3 Tb/s Over 128 Miles

AI clusters are hitting a networking wall, and China thinks it has an answer: fiber optic cable with a hollow, air-filled core instead of solid glass. In a new trial, YOFC and Decoli pushed 51.3 terabits per second across 206.5 km without electronic signal regeneration. Here's how hollow-core fiber works, why it could matter for AI data centers, and how it stacks up against Microsoft's own hollow-core bet.