The internet is one of the single biggest consumers of power in the world. There is constant pressure to find new solutions that will increase its speed and capacity.
The challenge was answered by a team of scientists from the University of Otago, in New Zealand, with the creation of a novel device that could enable the next generation of faster more energy efficient internet.
As reported, the microresonator optical frequency comb is a device that transforms a single colour of laser light into a rainbow of 160 different frequencies, with each bean totally in sync with each other and perfectly stable.
The Current Situation
The device, made out of a tiny disc of crystal, could replace hundreds of power-consuming lasers currently used to encode and send data around the world.
The internet is powered by lasers. Every email, mobile phone calls and website visit is encoded into data and sent around the world by laser light.
In order to cram more data down a single optical fibre, the information is split into different frequencies of light that can be transmitted in parallel.
The current infrastructure is struggling to cope with demand as internet consumption increases significantly.
Lasers only emit one colour at a time. Thus, if the application requires many different colours at once, more lasers will be needed.
All of them cost money and consume energy. The idea of these new frequency combs is that one colour is launched into the microresonator a whole range of new colours comes out.
The Microresonator
This breakthrough is the first milestone in a government-funded collaboration between scientists at the University of Otago and the University of Auckland, who are part of the Dodd-Walls Centre for Quantum and Photonic Technologies.
This is a virtual organisation gathering New Zealand’s top researchers working in the fields of light and quantum science.
It is a national Centre of Research Excellence (CoRE), hosted by the University of Otago, involving six NZ universities.
The research project has been awarded nearly NZ$ 1 million of Marsden Fund money.
The optical frequency combs are based on a very unusual optical effect that happens when the intensity of light builds up to extremely high levels.
A single colour of visible light is sent into the crystal disc along with a microwave signal. Because the crystal disc is such high quality, the light and microwave radiation gets trapped inside.
The light and microwave radiation would keep pouring in and bouncing around inside the crystal.
In most situations light never changes colour. But in this case, the intensity becomes so high that the light and the microwave radiation start merging and making different colours.
The phenomenon is known as a non-linear effect and it has taken the team many years to optimise.
Other Applications
The internet is just one of the possible applications for the new optical frequency combs.
Another use is high-precision spectroscopy, which uses laser light to study and identify the chemical composition, properties and structure of materials including diseases, explosives and chemicals.
Optical frequency combs have literally revolutionised every field of applications they have touched. They can be used for vibrational spectroscopy, distance measurement, telecommunications.
