If you want ultra-fast wireless internet, just get light to do the twist.
The wireless and fibre-optic links that make up the internet use electromagnetic waves to carry data as a series of pulses at a specific frequency. It is possible to increase the amount of data transmitted at a given frequency by twisting light beams in different ways. Each beam has a different angular momentum and acts as an independent channel in a larger, composite, beam.
Now Jian Wang, Alan Willner and colleagues at the University of Southern California in Los Angeles have used the twisting technique to transmit over a terabit of data per second. By comparison home WiFi routers typically run at around 50 megabits per second.
Because there are many ways to twist light, the team was able to combine beams with eight different types of twist, each carrying its own independent sequence of pulses.
Willner says the technique could be used between satellites in space, or over shorter distances on Earth. “It’s another dimension by which you can transmit data.”
Right now, it works only in free-space as current fibre-optic technology distorts twisted light.
Attribution: New Scientist