Media release

From: Springer Nature

New optical fibres could improve telecommunications

A newly developed hollow-core optical fibre, which guides light through air rather than glass, could offer the lowest ever recorded optical loss for a fibre, meaning the signal weakens less as it travels. This design, presented in Nature Photonics, also increases transmission speeds by 45% and allows more data to be transmitted over further distances before it requires boosting.

Optical fibres used for telecommunications typically feature a solid silica glass design, and despite decades of optimization, their signal loss has been a limiting factor. As such, about half of the light transmitted through the fibre is lost after about 20 kilometres, requiring the regular use of optical amplifiers to boost signals for longer distance transmission, such as intercontinental terrestrial or subsea links. Lowering the level of signal loss can be achieved over a small wavelength range, which limits the amount of data that can be transmitted, which has restricted optical communications over the past several decades.

Francesco Poletti and colleagues report an optical fibre made with a hollow air core surrounded by a fine pattern of thin silica rings to guide the light. When testing the fibres in laboratory experiments, the authors found that the fibre featured an optical loss of only 0.091 decibels per kilometre at a light wavelength commonly used in optical communications. As a result, light signals with suitable wavelengths could travel around 50% further before they required boosting. This design also provides a much broader transmission window (the range of wavelengths where light can travel with minimal signal loss and distortion) compared to previous optical fibre designs.

The authors note that this new type of optical fibre could potentially feature even lower losses by using a larger air core, though further research is needed to confirm this.