The amount of information that can be crammed into a beam of light can be increased by splitting the photon stream into different shaped spirals that act as independent channels.
Jian Wang at the Wuhan National Laboratory for Optoelectronics in China, Alan Willner at the University of Southern California, Los Angeles, and their team used the technique to send terabits of information per second through free space. The technique could be combined with more conventional methods of high-density data transfer — such as splitting a beam into two different polarizations or multiple wavelengths — to achieve massive data-flow.
The method could prove particularly well-suited to cable-free information transfer over short distances, or to communication in space.
Nature Photon. http://dx.doi.org/10.1038/nphoton.2012.138 (2012)