Trust the Facebook team to provide the world with something new and out-of-the box every time. This time the scientists at its Connectivity Lab have successfully discovered a new way through which one can detect light signals traveling through the air. This latest discovery is capable of creating fast optical wireless networks that could make internet services available even to the remotest of the places on the planet.
Currently, high-speed wired communication networks make use of lasers in order to carry the information through the optical fibers, but wireless networks are mostly based on either microwaves or radio frequencies.
A large number of people on the planet miss out on connecting to the internet because of unavailability of proper wireless communications infrastructure in the places they reside. The light-based wireless communication developed by the scientists at Facebook’s connectivity lab have the potential of making internet services available in places where deploying cell towers or optical fibers might be a problem, and that too in a super cost-effective manner.
The method of making use of laser light to move the information across the sky does have the potential of providing extremely high data capacity and bandwidths, but the main challenge that exists is to figure out a way through which one can pinpoint a very small laser beam carrying the information/data at a tiny light detector that is situated at some distance.
In the recent study by the researchers, they have discovered a new and better way to collect light and then concentrate it onto a very small photo-detector. The method they suggest is swapping the usage of traditional optics with fluorescent materials.
In order to achieve data rates of more than 2 Gbps, the researchers successfully merged this light collector, which actually has a 126 square centimeters surface capable of collecting light from any direction, with the current telecommunications technology.
The Facebook Connectivity Lab team demonstrated the usage of fluorescent optical fibers that absorb light of one colour and then emit another colour. This was made possible as the optical fibers absorbed light coming from any direction over a large surface, and then the emitted light traveled inside the optical fiber, which finally funnelled the light to a small but very fast photo-detector.
According to Tobias Tiecke, the lead researcher on the team, the fact that these fluorescent optical fibers emit a different colour than the one absorbed by them actually makes it possible to increase the brightness of the light which is entering the system.
He adds, that this very approach has been used in luminescent concentrators for solar light harvesting, wherein the colour conversion speed doesn’t hold prominence.
The Tobias Tiecke team have demonstrated how the same concept can be utilized for communication to overcome tracking and pointing challenges while achieving high speeds.
The researchers were successfully able to transmit more than 2 Gbps despite the 100 MHz bandwidth of the system by incorporating a simple signal modulation method famously called as orthogonal frequency division multiplexing (OFDM). For the unaware, OFDM is a method for encoding digital data for easy transmission of multiple data streams all at once.
According to Tiecke, his team was able to accomplish such high data rates by making use of commercially available materials that are not particularly made for communications purposes.
With this discovery, the social networking giant has actually brought light-based, wireless internet much closer to reality.