1 February 2013

Multi-tasking micro-LEDs targeted at Wi-Fi-like communications, while displaying information and illuminating homes

With the target of drawing academic and industrial expertise together to address the solid-state lighting/electronics interface and its implications for custom-controlled lighting systems, Scotland’s University of Strathclyde is already establishing the Intelligent Lighting Centre (ILC) in its Technology and Innovation Centre (TIC, a £103m research and innovation hub currently under construction).

Now, it is also leading a new £4.6m four-year program ‘Ultra-parallel visible light communications: UP-VLC’, funded by the UK Engineering and Physical Sciences Research Council (EPSRC) from September 2012 to August 2016, which is investigating solid-state lighting for next-generation optical communications. The program aims to pioneer new data communications infrastructure based on solid-state lighting, where lighting components provide both illumination and an ultra-high-bandwidth ‘light fidelity (Li-Fi)’ technology complementary to traditional radio wave and microwave Wi-Fi wireless communications.

Although the potential possibilities offered by Li-Fi are already being explored globally, a consortium of UK universities is pursuing a distinctive vision that could deliver enormous benefits, it is reckoned.

“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,” says professor Martin Dawson of the University of Strathclyde’s Institute of Photonics. “This is the kind of extraordinary, energy-saving parallelism that we believe our pioneering technology could deliver.”

Picture: The University of Strathclyde professor Martin Dawson, who is leading the research.

“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,” Dawson says. “This is technology that could start to touch every aspect of human life within a decade.”

Imperceptibly, 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. 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, it is reckoned.

But rather than developing Li-Fi LEDs around 1mm2 in size (on which other research concentrates), the EPSRC-funded team is developing micron-sized gallium nitride (GaN)-based LEDs that potentially offer major advantages, it is reckoned.
First, the LEDs are able to flicker on and off 1000 times quicker than the larger LEDs, so they can transmit data more quickly. Second, 1000 micron-sized LEDs would fit into the space occupied by a single larger 1mm2 LED, with each LED acting as a separate communication channel. A 1mm2-sized array of micron-sized LEDs could therefore communicate 1000 x 1000 (i.e. 1 million) times more information than one 1mm2 LED.

Each micron-sized LED would also act as a minute pixel. So 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 the same time as providing internet communications and lighting.

Eventually, it could be possible for the LEDs to incorporate sensing capabilities too, reckon the researchers. 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.

Spin-out companies related to this research are Glasgow-based mLED Ltd and Edinburgh-based pureVLC Ltd.  

For more information, see the audio slide show ‘Li-Fi Multi-tasking micro-lights could spark a communications revolution’ at the link below.

Tags: Strathclyde mLED microLED EPSRC

Visit: www.youtube.com/user/EPSRCvideo?feature=mhum

Visit: www.strath.ac.uk/Departments//Photonics