Bath hollow out fibres

Researchers at Bath University have discovered a way of speeding up the production of hollow-core optical fibres from around a week to a single day.

According to the university, initial tests also show that the procedure, described in the journal Optics Express, creates a fibre superior in virtually every respect to previous versions of the technology.

By narrowing the wall of glass around the large central hole by 100nm, the range of wavelengths that could be transmitted is broadened. This was done by omitting some of the most difficult steps in the production procedure, reducing the time taken and therefore ultimately the cost.

‘This is a major improvement in the development of hollow-core fibre technology,’ said Professor Jonathon Knight, of the centre for photonics and photonic materials at Bath University. ‘The fact that light has to travel through glass limits optical fibres in many ways. 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.

‘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.’

Developed as part of a European Commission-funded Framework 6 project NextGenPCF for applications in gas sensing, the improved performance means it also has potential in a range of fields, including laser machining, space science and pulsed beam delivery.

‘The consequences of being able to use light rather than electrical circuits to carry information will be fundamental,’ added Knight.

‘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.

‘For biomedical research, we can use these fibres to deliver light for diagnosis or surgery anywhere – even deep inside the body.

‘Almost any device where light is important or can be used, photonic crystal fibres can make more efficient, sensitive and powerful.’