In a whole new light

Once upon a time

FLICKERING lamps are normally a headache-inducing nuisance. But if the flickering happens millions of times a second—far faster than the eye can see or the brain respond to—then it might be harnessed to do something useful, like transmitting data. That, at least, is the idea behind a technology dubbed Li-Fi by its creators.

Li-Fi works with light-emitting diodes (LEDs), an increasingly popular way of illuminating homes and offices, and applies the same principle as that used by naval signal lamps. In other words, it encodes messages in flashes of light. It can be used to create a local-area network, or LAN, in a way similar to the LANs made possible by standard, microwave-based Wi-Fi.

Such LANs would, Li-Fi’s supporters believe, have two advantages over standard Wi-Fi. One is that light does not penetrate walls. A Li-Fi LAN in a windowless room is thus more secure than one using Wi-Fi, whose microwave signals pass easily through most building materials and can thus be listened to by outsiders. The other advantage is that light does not interfere with radio or radar signals in the way that…Continue reading
Source: Economist