For super fast data, give light a twist

Twisted beams of light are able to transmit more than 85,000 times more data per second than broadband cable, a new study shows.

The work might be used to build high-speed satellite communication links, short free-space terrestrial links, or potentially be adapted for use in the fiber optic cables that are used by some Internet service providers.

“You’re able to do things with light that you can’t do with electricity,” says Alan Willner, electrical engineering professor at the University of Southern California. “That’s the beauty of light; it’s a bunch of photons that can be manipulated in many different ways at very high speed.”

As reported in the journal Nature Photonics, Willner and an international team of researchers used beam-twisting “phase holograms” to manipulate eight beams of light so that each one twisted in a DNA-like helical shape as it propagated in free space. Each of the beams had its own individual twist and can be encoded with “1″ and “0″ data bits, making each an independent data stream—much like separate channels on your radio.

Their demonstration transmitted the data over open space in a lab, attempting to simulate the sort of communications that might occur between satellites in space. Among the next steps for the research field will be to advance how it can be adapted for use in fiber optics, like those frequently used to transmit data over the Internet.

The team’s work builds on research done by Leslie Allen, Anton Zeilinger, Miles Padgett, and their colleagues at several European universities. “We didn’t invent the twisting of light, but we took the concept and ramped it up to a terabit-per-second,” Willner says.

Jian Wang, the lead author, left USC after completing this research and is now a professor at the Huazhong University of Science and Technology in China.

Researchers from the US, China, Pakistan, and Israel contributed to the research that was funded by the Defense Advance Research Projects Agency (DARPA) under the InPho (Information in a Photon) program.

June 25, 2012

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