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. The previous record over a single optical  fiber — 26 terabits per second, set by  Karlsruhe Institute of Technology way  back in 2011 — had remained unbroken  for a surprisingly long period of time.  DTU set a series of single-fiber world  records in 2009 and 2011, but had since  been forced to sit in Karlsruhe’s shadow  — until now. This was obviously a pain  point for the DTU researchers — the press release [Danish] announcing the  new world record actually calls out  Karlsruhe by name. I guess a bit of  friendly competition never hurt anyone  though, right?  The main thing about this world record  is DTU’s use of a single laser over a  single fiber. There have been plenty of  network demonstrations of hundreds or  even thousands of terabits (petabits) per second with multiple lasers over multiple fibers — but those demos are so far  removed from the reality of fiber-optic  networking that they’re not really worth  discussing. When we talk about  commercial fiber-optic links, we’re nearly always talking about single-laser-single- fiber, because that’s what the entire  internet backbone is built upon. In other  words, the techniques used by DTU to  hit 43Tbps actually have a chance of  making it into real-world networks in the next few years. You might soon be able  to download a TV show or movie in quite literally the blink of an eye. [Read: Infinite-capacity wireless vortex beams .] 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 .  NTT’s 7- and 19-core multi-core fiber Wavelength-division multiplexing Beyond the DTU’s use of multi-core  fiber, there’s sadly very little info on how they actually squeezed 5.4 terabytes of  data per second over a single fiber. The  usual method of boosting speeds over  fiber is either SDM or WDM (spatial and  wavelength-division multiplexing) — i.e.  using different frequencies of light for  each signal, or staggering each signal by  a few microseconds, so that the signals  don’t collide. 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. (Customers of awful ISPs excepted, of course.)
source : Extremetech.com