Researchers at Eindhoven University of Technology have come up with a solution to slow wifi. Use a wireless network based on harmless infrared rays. The capacity is not only huge (more than 40Gbit/s per ray) but also there is no need to share since every device gets its own ray of light. This was the subject for which TU/e researcher Joanne Oh received her PhD degree with the 'cum laude' distinction last week.

The system conceived in Eindhoven is simple and, in principle, cheap to set up. The wireless data comes from a few central 'light antennas', for instance mounted on the ceiling, which are able to very precisely direct the rays of light supplied by an optical fiber. Since there are no moving parts, it is maintenance-free and needs no power: the antennas contain a pair of gratings that radiate light rays of different wavelengths at different angles ('passive diffraction gratings').