'Twisted Light' Beams Data at a Staggering 2.56 Terabits Per Second
Damon Poeter By Damon Poeter
June 25, 2012 09:29pm EST
How would you like to be able to download a feature film onto your smartphone in a single second? How about 70 movies in a blink of an eye?
No phone has the storage capacity to handle such a monumental data dump, of course. But it's fun to imagine the possibilities of "twisted light," a new approach to transmitting data that can hit speeds of 2.56 terabits per second (Tbps), according to an international team of researchers publishing in this week's issue of Nature Photonics.
That's 85,000 times faster than the 30 Mbps broadband Internet we enjoy today, according to Innovation News Daily. Or, to put it into better perspective, at such data transfer rates, you could transmit 70 full-length DVDs over the air in about a second.
Researchers from the University of Southern California, China, Pakistan, and Israel say their data transmission process gets around the need for bandwidth entirely. That's because the twists in the twisted laser beams they use to ferry data through open space "can effectively create the equivalent of a new data stream channel—similar to a radio having separate channels—without the need for more bandwidth," Innovation News Daily reported.
"We didn't invent the twisting of light, but we took the concept and ramped it up to a terabit-per-second," Alan Willner, an electrical engineering professor at USC, told the site.
The scientists used four light beams which were "multiplexed and demultiplexed" to ramp transmission speed up to 1.37 Tbps and then deployed "two groups of concentric rings of eight polarization-multiplexed 20 × 4 Gbit s−1 16-QAM-carrying orbital angular momentum beams" to crank it up to 2.56 Tbps, according to the Nature Photonics abstract.
But don't expect to see twisted light Wi-Fi hot spots any time soon. Earth's atmosphere interferes with the beaming of data via twisted light over all but very short distances. But it does work a treat in space, apparently, and the Pentagon's Defense Advance Research Projects Agency (DARPA) is reportedly testing twisted light as a means of communication between satellites.
Innovation News Daily also reported that adaptive optics technology can partially offset atmospheric inference in twisted light transmissions over fiber optic cables.
Earlier this year, scientists at the University of Pittsburgh used a different technique to transmit data thousands of times faster than is possible today on wireless networks. The team led by Hrvoje Petek, a physics and chemistry professor in Pitt's Kenneth P. Dietrich School of Arts and Sciences, successfully created what they call a "frequency comb" that "spans more than 100 terahertz (THz) of bandwidth by exciting a coherent collective of atomic motions in a semiconductor silicon crystal."
Jian Wang,Jeng-Yuan Yang,Irfan M. Fazal,Nisar Ahmed,Yan Yan,Hao Huang,Yongxiong Ren,Yang Yue & Alan E. Willner