Data link trial: Chinese team finds hollow-core fibre cuts lag 30% across 1,000km

Light travels through conventional optical fibres at about 200,000km per second – about two-thirds the speed it travels in a vacuum – because the signals are passing through solid glass.When vast amounts of data are exchanged between computing centres hundreds or thousands of kilometres apart, this difference amounts to a substantial delay.Now, Chinese researchers have unveiled optical fibre that replaces the solid glass core with air, cutting the data transmission delay by about 30 per cent over 1,000km (621 miles), they say.