news digest ♦ LEDs LEDs
Sparking up communications with Li-Fi
Minute LED lights could deliver Wi-Fi-like internet communications
The University of Strathclyde says it has made a breakthrough in displaying information and illuminating homes,
The aim of the universities project is to develop the innovative technology to unleash the full potential of “Li-Fi”.
This is the transmission of internet communications using visible light, rather than via the radio waves and microwaves currently in use.
continues, “The Universities of Cambridge, Edinburgh, Oxford and St Andrews are all working with us, bringing specific expertise in complementary areas that will equip the consortium to tackle the many formidable challenges involved - in electronics, computing and materials, for instance - in making this vision a reality. This is technology that could start to touch every aspect of human life within a decade.”
Underpinning Li-Fi is the use of LEDs,a rapidly spreading lighting technology which is expected to become dominant over the next 20 years.
LEDs flicker on and off thousands of times a second. By altering the length of the flickers, it is possible to send digital information to specially- adapted PCs and other electronic devices - making Li-Fi the digital equivalent of Morse Code.
This would make the visible part of the electromagnetic spectrum available for internet communications, easing pressure on the increasingly crowded parts of the spectrum currently being used.
But rather than developing Li-Fi LEDs around 1mm2 in size, which other researchers around the world are concentrating on, the EPSRC-funded team is developing micron-sized LEDs which potentially offer a number of major advantages.
Micron LED
Although the potential possibilities offered by Li-Fi are already being explored globally, the EPSRC funded consortium of UK universities (see below) is pursuing a radical, distinctive vision that could deliver big benefits.
Martin Dawson, a professor at Strathclyde, who is leading the four-year initiative, says, “Imagine an LED array beside a motorway helping to light the road, displaying the latest traffic updates and transmitting internet information wirelessly to passengers’ laptops, netbooks and smartphones. This is the kind of extraordinary, energy-saving parallelism that we believe our pioneering technology could deliver.”
To enable the potential to be realised, the consortium has drawn together a wide branch of Li- Fi research experts. Dawson, of the University’s Institute of Photonics,
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www.compoundsemiconductor.net January/February 2013
Firstly, the tiny LEDs are able to flicker on and off 1,000 times quicker than the larger LEDs, meaning that they can transmit data more quickly.
Secondly, 1,000 micron-sized LEDs would fit into the space occupied by a single larger 1mm2 LED, with each of these tiny LEDs acting as a separate communication channel. A 1mm2 sized array of micron-sized LEDs could therefore communicate 1,000 x 1,000 - or, in other words, one million - times as much information as one 1mm2 LED.
Each micron-sized LED would also act as a tiny pixel. This means one large LED array display, for example, used to light a living room, a meeting room or the interior of an aircraft, could also be used as a screen displaying information, at exactly the same time as providing internet communications and lighting.
Eventually, it could even be possible for the LEDs to
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