Tiny LEDs could spark a communications revolution
31 January 2013
LEDs could deliver Wi-Fi-like communications, while fulfilling their usual role of illuminating homes, thanks to research led by the University of Strathclyde.
The aim is to develop the technology to unleash the full potential of “Li-Fi” – the transmission of internet communications using visible light, rather than via wireless and microwave.
Although the potential possibilities offered by Li-Fi are already being explored globally, this Engineering and Physical Sciences Research Council (EPSRC)-funded consortium of UK universities is pursuing a radical, distinctive vision that could deliver enormous benefits.
Professor Martin Dawson, of Strathclyde, who is leading the four-year initiative, said: “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 this potential to be realised, the consortium has drawn together an expert team which it believes is unmatched by any other Li-Fi research team in the world.
Professor Dawson said: “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 ability to modulate LEDs at frequencies of several kiloHertz. By altering the frequency, it is possible to send digital information to specially-adapted PCs and other electronic devices. This would make the visible part of the electromagnetic spectrum available for internet communications, easing pressure on other, increasingly crowded, parts of the spectrum.
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 tiny, micron-sized LEDs which potentially offer a number of major advantages.
Firstly, the tiny LEDs can be modulated at much higher frequencies - 1,000 times more than the larger LEDs, providing greater bandwidth (1Gb/s is proposed - much faster than existing Wi-Fi). 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 incorporate sensing capabilities too. For example, a mobile phone could be equipped with a flash that – when pointed at a shop display in which every item has been given an electronic price tag – could display the price of these items.
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