43Tbps over a single fiber: World’s fastest network would let you download a movie in 0.2 milliseconds

A research group at the Technical University of Denmark (DTU),

which was the first to break the one-terabit barrier in 2009, has today managed to squeeze 43 terabits per second over a single optical fiber with just one laser transmitter. In a more user-friendly unit, 43Tbps is equivalent to a transfer rate of around 5.4 terabytes per second — or 5,375 gigabytes to be exact. Yes, if you had your hands on DTU’s new fiber-optic network, you could transfer the entire contents of your 1TB hard drive in a fifth of a second — or, to put it another way, a 1GB DVD rip in 0.2 milliseconds.

How did the DTU hit 43Tbps and steal the world record away from Karlsruhe? Well, rather amusingly, they kind of cheated. While the researchers did only use a single laser, it used multi-core fiber. This is still a single filament of glass fiber, but it has multiple individual channels that can each carry their own optical signal. In this case, DTU used multi-core optical fibers with seven cores, produced by Japanese telecom giant NTT. Back in 2011 when Karlsruhe set its 26Tbps record (with a single-core fiber), multi-core fibers were both difficult and expensive to manufacture — now, in 2014, it would seem the bugs have been ironed out and NTT is moving ahead with commercial deployments. The photo at the top of the story, incidentally, is an experimental hollow-multi-core fiber developed by DARPA.

 Currently, the fastest commercial single-laser-single-fiber network connections max out at just 100Gbps (100 Gigabit Ethernet). The IEEE is currently investigating the feasibility of either a 400Gbps or 1Tbps Ethernet standard, with ratification not due until 2017 or later. Obviously DTU’s 43Tbps won’t have much in the way of real-world repercussions for now — but it’s a very good sign that we’re not going to run out of internet bandwidth any time soon.