2.5 terabits per second

It may one day be commonplace to download data packages the equivalent of 70 DVDs in one second, say scientists, citing research that shows a new high-speed data transfer breaking records.
A team of U.S. researchers say they have discovered a process by which to transmit upwards of 2.56 terabits of data per second using twisted beams of light. The technology has potential applications for high-speed satellite communication links, short free-space terrestrial links or could be adapted for use in the fiber optic cables used by some Internet service providers, researchers said.

Researchers noted that the test conducted resulted in data transfer speeds 85,000 times faster than broadband internet speeds, some of the fastest ever recorded.  The test was conducted by harnessing the power of light, which scientists manipulated in order to better facilitate the transfer of data. The present study saw a single beam of light carry 2.5 terabits per second carried over a distance of 1 meter, but the method could be adapted for long distance, say scientists.


"We didn't invent the twisting of light, but we took the concept and ramped it up to a terabit-per-second," said Alan Willner, electrical engineering professor at the University of Southern California in Los Angeles.
"You're able to do things with light that you can't do with electricity," he added. "That's the beauty of light; it's a bunch of photons that can be manipulated in many different ways at very high speed."
Mr. Willner and his colleagues 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. The resulting holograms were twisted in such a manner that they could then be  encoded with "1″ and "0″ data bits, making each an independent data stream — much like separate channels on your radio.
Previously it was revealed that beams with different orbital angular momentum (OAM) states — different degrees of spin — could be used to carry more data, and this new milestone builds on that idea, said researchers.

The team noted a number of potential practicably uses for the research. Scientists noted that the demonstration transmitted the data over open space in a lab, attempting to simulate the sort of communications that might occur between satellites in space, say researchers, noting that the results may have uses outside of commercial, including the U.S. military.
The research is particularly timely in that a recent report notes that the U.S. Military is currently searching for secure smartphones for U.S. troops stationed abroad. The Defense Advanced Research Projects Agency (DARPA) has now assigned Invincea  to fortify Android-based phones and tablets so they are safe in soldiers' hands. The $21 million grant to the company is a window into how pervasive networked technologies have become in the military – and the market that has opened up to secure them, the New York Times reports.
 
While the study is not the first to utilize light for transferring large quantities of data, the research could open the door to a wide range of uses. Advances are likely to see utilization in a number of scientific field, but could also advance medical realms, by detecting molecules of toxic substances and improving laser assisted surgical techniques.
Most data traffic in optical fibres around the world is made up of different data streams on slightly different colours of light, which are split into their constituent colours at the receiving end in a technique called multiplexing. The team said that the research could ultimately be used in homes, but that the technology needed for everyday use is likely year away.

To fully realise OAM's potential, similar multiplexing of different "twists" must be developed, scientists said.
The team conducting the researcher reportedly included Jian Wang, Jeng-Yuan Yang, Irfan M. Fazal, Nisar Ahmed, Yan Yan, Hao Huang, Yongxiong Ren and Yang Yue from USC; Samuel Dolinar from NASA's Jet Propulsion Laboratory; and Moshe Tur from Tel Aviv University.