You can use lasers in all sorts of exiting ways. We have known for a while that you can use lasers to transmit wireless internet. Way back in 2012, New Scientist published an article suggesting that while lasers would be impractical for sharing data outside due to weather such as rain and fog, lasers could definitely be an option for transmitting data indoors. Well, now there’s a new idea. What about combining wi-fi with your ceiling light?This is the idea that Boon Ooi and his team from KAUST have been pursuing with their intuitive design for a light bulb that combines LED technology and wi-fi into one multifunctional solution.
Wi-fi Lasers
Facebook has recently proposed bringing wi-fi to otherwise hard to reach places using lasers. The idea is that because it would be challenging to install optical fibres or cell towers, lasers would be a simpler solution.
In their recent studies, Facebook have demonstrated a method using a 126㎠ surface made of fluorescent materials to collect light. This light is then focussed and concentrated onto a small photodetector. Amazingly, the surface can collect light from any direction and then, when combined with existing telecommunications technology, it can achieve data rates of more than 2 gigabits-per-second (Gbps).
While many shapes are possible, the researchers demonstrated their idea using a bulb-shaped light collector made out of fluorescent optical fibres. The advantage of the bulb shape is that it can offer omnidirectional sensitivity and a very large bandwidth. This means that if you were to connect using a mobile device, you would be able to move about the room without losing connection.
Changing Colours
The researchers at Facebook used plastic optical fibres containing organic dye molecules to absorb blue light and emit green light. This, claims Tobias Tiecke, leader of the research group, ‘makes it possible to increase the brightness of the light entering the system.’
This system makes the fast transfer of information possible because it takes less than 2 nanoseconds for the blue light to be absorbed and the green light to be emitted. In combination with OFDM (orthogonal frequency division multiplexing – a method of encoding data so that multiple data streams can be transmitted at once), communicating with lasers is becoming commercially viable as a new and exciting way to connect the world.
Creating White Light
Moving on from Facebook’s research, Professor of Electrical Engineering, Boon Ooi from King Abdulla University of Science and Technology in Saudi Arabia is experimenting with a nanocrystal-based converter that could enable much higher data transfer rates and produce a warm white light to boot.
The nanocrystals, roughly 8 nanometres in size, incorporated nitride phosphor so that when they are illuminated by blue laser light, they emit green light while the nitride emits red light. The combination of the green and red light produces a warm white light. This is very similar to the way that LEDs work using phosphorus.
The optical process is not just about creating white light, though, Ooi’s team have also shown that this method is 40 times faster than using phosphorus alone and can transmit data at a rate of two billion bits per second.
Laser Lightbulb Wi-fi
The white light demonstrated by Ooi and his team is comparable to that of current LED technology, giving rise to the natural idea that at some point soon we could be looking at lights that don’t just illuminate the room but provide internet connection too. This is an incredibly exciting idea that could have a huge impact on the way that we use energy and connect the world to the internet.
With the lightbulb being the perfect shape for receiving data and current LED technology pointing in a similar direction to Ooi’s ideas for fast data transmission, it appears that this technology has become an inevitable solution to the various challenges of our increasingly technological society.
Using this kind of visible-light communication seems like a natural step to more efficient use of energy. It also seems a more intuitive design than building cell towers or installing optical fibres in areas that don’t already have this technology.
It’s exciting to think that wi-fi could literally light up the world.
