Fibre optics

“Speed of Light” Fibre Optics?

Fibre optics

Much of the discussion about internet connectivity in the last few years has been about the move from the old copper cables that are essentially the same as when they were first installed over 100 years ago, and modern fibre optics whether that is to the home (FTTH) or to the cabinet (FTTC). Either way the change in speed is huge, and this open up the use of more high bandwidth services in the future such as HD 3D streaming and gameplay.

In common parlance, people often refer to fibre optic cables sold by companies such as MCL Data Solutions, allow for the data to travel at the speed of light, but this is not quite true. Conventional fibre optic cable is made from two types of glass: a thick layer of glass cadding coated in a polymer for protection; and a thin silica glass core that actually carries the light. As the cladding has a lower refractive index than the core, the light is continuously reflected back and forth down the core in one direction, a process known as total internal reflection. This continual “bouncing” down the core causes the light to slow as it propagates, meaning the light (and data) only travels at around 70% of the speed of light in a vacuum.

A team at the University of Southampton claim to have brought their data transmission rates up to 99.7% of the speed of light, with notable improvements over conventional fibre,with a technology called “hollow-core optical cables”, with research published in the journal Nature Photonics. These hollow core cables have an air-filled fibre at the centre, surrounded by a fine mesh of struts made of silica glass which allows the light to propagate 31% faster, and reducing latency.

At this stage, it is still early days in the research on these hollow core fibres, with tests only performed over short kilometre scale distances, not hundreds of metres, and the issues of how to splice the fibres and prevent moisture getting into the holes still need to be addressed. Faster and lower latency connections, however, could be very useful in the world of super-fast trading finance, or even just for connecting servers together within a server farm for pushing data around even faster.

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