
While current optical fibres transmit information via pulses of light that travel in a glass core, hollow-core fibres transmit optical information in a core of air.
“The fact that light has to travel through glass [in standard optical fibres] limits them in many ways,” said Jonathan Knight, who developed the new procedure at the University of Bath’s Centre for Photonics & Photonic Materials.
“For example, the glass can be damaged if there is too much light. Also, the glass causes short pulses of light to spread out in a blurring effect that makes them less well-defined. This limits its usefulness in telecommunications and other applications.”
“Hence, fibres in which light travels in air down a hollow core hold great promise for a next generation of optical fibres with performance enhanced in many ways.”
By narrowing the wall of glass around the hollow core by just a hundred nanometres, Knight and his team of researchers were able to reduce the level of detail required in the manufacture of hollow-core fibres.
The simplified procedure reduces the time required to make the fibres from around a week to a single day, reducing the overall cost of fabrication.
“This is a major improvement in the development of hollow-core fibre technology,” Knight said. “It will make optical fibres many times more powerful and brings the day when information technology will consist of optical devices rather than less efficient electronic circuits much closer.”
Electronic circuits transmit information via electrons that pass through copper wires. As such, data transfer speeds are limited by bandwidth, which determines the number of electrons – and hence the amount of information - that can pass through the wire at any one time.
The use of light in optical fibres overcomes conventional problems of bandwidth, hence increasing the speed and efficiency of data transfer.
Hollow-core optical fibres could be used in faster optical telecommunications, more powerful and accurate laser machining, and a cheaper generation of x-ray or ultra-violet light for use in biomedical and surgical optics.
“The consequences of being able to use light rather than electrical circuits to carry information will be fundamental,” Knight said.
“Almost any device where light is important or can be used, photonic crystal fibres can make more efficient, sensitive and powerful.”
The new technology is expected to have a significant impact in a range of fields such as laser design and pulsed beam delivery, spectroscopy, biomedical and surgical optics, laser machining, the automotive industry and space science.