Twisting light waves to increase their data capacity

BBC : Researchers have succeeded in manipulating the orbital angular momentum (OAM) of light waves to greatly increase their transmission capacity. Unlike spin angular momentum, or polarization, which relies on light waves wiggling in different directions, OAM relies on light waves wiggling with different amounts of twist, like screws with different numbers of threads. Bo Thidé of the Swedish Institute of Space Physics and colleagues demonstrated the principle by transmitting two radio channels on the same frequency but in two different OAM states. In their paper , published in the New Journal of Physics, they show how they were able to increase radio transmission capacity without increasing bandwidth. Such research could boost the data-carrying capacity of optical fibers and wireless networks.