French-American über-firm Alcatel-Lucent has announced its boffins have broken the record speed for data transfer over a single fibre optic cable. The figure of 25.6 Terabits per second was announced in a paper presented to a conference in Anaheim, California.

The previous high, 14 Terabits per second, was established in September last year. A Terabit, in case you were wondering, works out at a trillion bits.

The record is for the transfer of "optical data over a single fibre strand". The process uses 160 Wavelength-Division Multiplexed (WDM) channels - that's a bandwidth figure. In this case, it's enough to transfer an incredible 600 DVDs-worth of data per second.

"Optical networking is a critical enabler of the broadband IP revolution we are seeing throughout the world today," said Romano Valussi, president of Alcatel-Lucent's Optics activities. "The experience we are developing in these tests will help Alcatel-Lucent design the most efficient, highest bandwidth systems possible to benefit our customers."

Alcatel-Lucent says the figure was achieved by its experts in optimising the efficiency of optical networks, using both "wavelength and polarisation multiplexing [to maximise bandwidth], and general mastery of the physical layer of optical networking."

Scientists from the National Institute of Information and Communications Technologies in Tokyo (NTIICT) were also involved.