China has completed the world's first 1,000-kilometre bidirectional real-time transmission test using hollow-core optical fibre, marking a major breakthrough in next-generation communications technology.

The experiment achieved simultaneous two-way transmission at 64 terabits per second in each direction over a 1,007.48-kilometre link. This is equivalent to uploading and downloading 160 4K films per second, based on a file size of 50 GB each. A one-way transmission across the link took just 3.43 milliseconds.

The link was assembled using more than 300 spools of hollow-core optical fibre, each containing two to five kilometres of fibre.

Compared with leading solid-core optical fibres, the technology doubles transmission capacity and extends transmission distance by 60 percent. It also reduces signal latency by around 30 percent by transmitting signals through gas rather than solid glass. The test distance was 50 times longer than previous comparable hollow-core fibre experiments, highlighting its potential for future high-capacity, low-latency computing networks.