One of the main problems with rolling out super-fast fiber optic internet services to people around the country is cost. Google has found this out the hard way with its Google Fiber deployments being axed in some areas and TV service cut out of the picture in all new markets. Finishing out the "last mile" of those networks to get fiber speeds to homes has proven to be costlier than expected, but there is new hope for the blazing fast internet speeds we all want. That new hope is called "twisted" light.
Twisted light is a form of wireless communications able to handle high-capacity data transmission and could make fiber optics obsolete for last mile networks. A team of physicists that hail from the UK, Germany, New Zealand, and Canada have been working on twisted light, specifically on something called "optical angular momentum" or OAM. The team thinks they could overcome the current issues with using twisted light across open spaces.
Twisted light is when photons are twisted by passing them through a special type of hologram, which gives those photons a twist known as OAM. These intertwined twists in the photons allow them to carry additional data compared to conventional digital optical communications where photons are ones and zeros. The University of Glasgow writes that this is akin to placing letters along with the ones and zeros. This means that twisted photons have the potential to create higher bandwidth communications technology.
The challenge currently is that twisted light transmission across open spaces is very susceptible to scattering; so much so that simple changes in atmospheric pressure across open spaces can scatter the light beams causing information transmitted to be lost. The team of researchers is currently testing OAM in a free space in Erlangen, Germany. In this test, twisted light data is being passed over a 1.6km length with the light data transmitted over fields and streets that are close to high-rise buildings.
Dr. Martin Lavery, head of the Structured Photonics Research Group at University of Glasgow, lead author on the team’s research paper, said, "In an age where our global data consumption is growing at an exponential rate, there is mounting pressure to discover new methods of information carrying that can keep up with the huge uptake in data across the world."
"A complete, working optical angular momentum communications system capable of transmitting data wirelessly across free space has the potential to transform online access for developing countries, defence systems and cities around the world."
The team’s testing area has highlighted issues that will have to be overcome for twisted light communications to become a reality in the future. The experiment found that shaped phase fronts, which are integral to high-bandwidth data transfers, are fragile. The result of the experiments has led the team to believe they can overcome the issues seen with fragility now that they know the issues exist.
Dr. Lavery added, "With these new developments, we are confident that we can now re-think our approaches to channel modelling and the requirement places on adaptive optics systems. We are getting ever closer to developing OAM communications that can be deployed in a real urban setting."
"We want to start a conversation about the issues that need to be addressed and how we are going to move towards the resolution."