New research at Alcatel-Lucent‘s (ALU) Bell Labs moves the speedometer up to 400 Gbps. Jordan Novet explains in the GigaOm article, A gigabit is not enough. New research takes us to 400 Gbps. According to the article, the Bell Lab researchers have figured out a way to cancel out the noise inside fiber data transmission. They cancel the noise, in the same way, your Bose noise-canceling headphones work, by sending more information to counter the noise of the crying kid in 4-C on Flight 1501.
The Bell Labs team calls this “phase conjugation.” According to Nature Photonics (rb- it will cost you $32.00 the read the actual article), this means sending two streams of data through a single fiber-optic pipe. Phase conjugation sends “twin waves” of light (information) down the fiber in opposing phases, rather than just one. Both streams are pulled back together at the destination to compare the streams and remove the noise. The clean output lets Bell Labs crank up the power to drive the signal at higher speeds further.
Mr. Novet explains that the pairing of signals, in essence, cancels out the ups and downs, peaks and troughs, in physics terms, of data. That means the signal-to-noise ratio improves, which lets fiber optic communications travel farther without more gear along the way to boost the signal. The researchers used this technique to do 400 Gbps across the record distance 
of over 7,900 miles.
Lead author Dr. Xiang Liu told BBC News, “This concept, looking back, is quite easy to understand, but surprisingly, nobody did this before.”
rb-
Most of the articles are impressed with the distance the Bell Labs researchers were able to achieve. Phase conjugation may eventually allow telcos to deploy trans-continental links or undersea links without having to deploy mid-span signal re-generators.
The GigaOm article points out that speeds faster than 400 Gbps are not unheard of. I have covered the increasing speeds here, here, and here. GigaOm points out that researchers have managed to send data at speeds exceeding 100 terabits per second, although it wasn’t clear how far the speeds could be sustained. Last year Verizon clocked in at 21.7 terabits per second across more than 900 miles of broadband with the help of NEC’s “superchannels.”
The Bell Labs researchers have taken a different tack. This is a huge deal because it looks like it’s possible to get higher speeds without replacing hardware at the bottom of the sea.
Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.
The Holey Optochip is green
A single 90-nanometer IBM CMOS transceiver 
The trick is to use what is known as a “
Professor Freude told the BBC that the current design outperforms earlier approaches simply by moving all the time delays further apart and that it is a technology that could be integrated onto a silicon chip – making it a better candidate for scaling up to commercial use.