Twisting Light Sends Data Speeds Soaring

Beams of light twisted and combined to transmit data at up to 2.56 terabits per second soon could lead to the fabrication of high-speed satellite communication links or be adapted for use in fiber optics.

An international team led by University of Southern California Viterbi School of Engineering researchers has developed a twisted-light system that transmits more than 85,000 times more data per second than broadband cable, which supports up to about 30 megabits per second.

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

The scientists 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 beam can be encoded with “1” and “0” data bits, making each an independent data stream – similar to separate channels on a radio.

To simulate the type of communications that occur between satellites in space, the team demonstrated free-space data transmission.

Next, the researchers plan to advance how the system can be adapted for use in fiber optics.

Multiple data channels, each on a different light beam having a “front” that twists in a different helical shape as it propagates, can be combined (i.e., multiplexed) together to produce an aggregate of terabits per second of free-space data transmission capacity. (Image: Alan Willner et al)

Their 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 said.

Researchers from the US, China, Pakistan and Israel contributed to the research, which was funded by DARPA under the InPho (Information in a Photon) program.

The study appeared in Nature Photonics.

For more information, visit: www.usc.edu