Bach Seat

All the data the reaches every Internet-connected home, business, and mobile device get there via thousands of miles of laser-filled glass, copper, or plastic wires. Firms large and small are constantly developing new ways to pack as much data as possible into these cables (rb- I’ve covered many of these developments here, here, and here). Here is a new theory that uses twisted light.

Signe Brewster at GigaOM wrote about a major leap in how much data Comcast (CMCSA), AT&T (T), and Verizon (VZ) can send down the Internet tubes. Researchers at Boston University and the University of Southern California were able to send 1.6 terabits per second of data (rb- equal to transmitting eight Blu-Ray DVDs every second) 1 kilometer in the lab. They have developed data beams that travel in a spiral instead of a straight line without getting jumbled together.

Orbital angular momentum beams

They keep the beams in order by generating optical vortices (a.k.a orbital angular momentum, or OAM beams) with what ScienceNews called a spatial light modulator. Most researchers thought that OAM beams were unstable in fiber. That was until Siddharth Ramachandran, an electrical engineer, and leader of the Boston University team designed an optical fiber that can propagate the twisted light. The BU team created an OAM fiber with four modes (varying index of refraction an optical fiber typically has two modes) and showed that for each mode, they could send data through a one-kilometer fiber in different colors, resulting in a transmission capacity of 1.6 terabits per second.

The DARPA-funded search for ways to squeeze ever more information into the fiber-optic cables that carry it could not come at a better time as mobile devices fuels rapidly growing demands on the Internet. BU’s Ramachandran told Futurity.org, “Our discovery …  has profound implications for a variety of scientific and technological fields that have exploited the unique properties of OAM-carrying light, including the use of such beams for enhancing data capacity in fibers.”  The result is more data in the same length of cable. Science (subscription required) published the new research in its June 28 edition.

10 beams of twisted light in custom fiber

The spiral beams can be combined with existing bandwidth boosting techniques, such as sending many beams through a cable at once according to the author. The spiral beams are sent along different paths and made to be different colors, which differentiates them and lowers the computing necessary to process them once they reach their destination.

The researchers say they can send up to 10 concurrent beams through their custom fiber. They hope to squeeze more data into each of those beams using methods already exploited by the telecom industry. “We showed a new degree of freedom in which we could transmit information,” says Professor Ramachandran.

rb-

As this technology sits now, it has limited use. The 1.1 Km distance will limit it to the data center, once Cisco (CSCO), Intel (INTC), and HP (HPQ) figure out how to deal with the data.

Then there is the issue of re-wiring the backbone with new cables to accept the OAM beams, at&t alone has 77,000 route miles (PDF) of fiber optic cable in the U.S. The BU professor told GigaOM that the team manufactured its fiber at a commercial facility using standard methods, so if it were mass-produced, the fiber should not cost much more than those now in use.

The current speed record, set in 2011, is 100 Tbps, 1.6 Tbps seems kind of wimpy in comparison. which is faster than this cable.

Related articles

• New Fiber-Optic Technology Demonstrated at Extreme 1.6 Terabit Per Second Speed (scienceworldreport.com)

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.