Researchers at Oxford University have developed a new technology that delivers ultra-high-speed Wi-Fi (224 Gbps) via light beams. In the future, “Li-Fi” could allow Internet users to download a 1.5Gb movie in the blink of an eye.

The true enormity of this step change in Wi-Fi download speed becomes apparent when one considers that current high speed fibre optic cables deliver 1Gbps. Moreover, in the USA, access to 1Gbps is only offered by a small number of providers in a few locations. It is estimated that, ultimately, Li-Fi technology could offer up to 3 Terabits per second.

There are inherent problems with using light as a data transfer medium. Cables “contain” the light, using internal reflection to guide the beam along its way. Containing the beam in the air is another matter altogether. To address the issue, the Oxford boffins have fitted both transmitter and receiver with holographic beam steering technology and then created programmable diffraction using an array of liquid crystals. And rather than using visible light, the researchers have used infrared light at 1550nm, so invisible to the naked eye. Clever stuff indeed.

The technology is limited in its application, since light cannot pass through opaque objects. Therefore both transmitter and receiver need an uninterrupted direct line of sight. In addition, download speed diminishes as the receiver’s field of view narrows. Despite these limitations, the researchers assert it is only a matter of time before a tracker system is developed which will potentially allow a laptop to connect from a random spot on a table.

The research is part of a broader ambition to develop light-based wireless communications which use the light which already illuminates a room.

Sources:

1. Tech Times:
   'Oxford Researchers Achieve 224Gbps Connection Using Light: Li-Fi Will Let You Download 1.5GB Movie in a blink.
2. The Telegraph:
   Researchers develop 100Gps light based wireless network.