Bright future for photonics

Optical fibres that change the wavelength – and therefore colour – of light have been developed by physicists at the University of Bath.

A fibre drawing tower uses a precisely controlled furnace to melt and stretch glass optical fibre to diameters as narrow as a human hair. The glass fibres – which have a honeycomb structure of microscopic holes running along their length – can have different optical properties depending on their structure and researchers hope the fibres could find use in applications ranging from diagnosing cancer to engineering jet engines.

“Generally lasers are high energy light sources of a single colour,” said Dr William Wadsworth, Director of the University’s Centre for Photonics and Photonic Materials. “However, the supercontinuum fibre converts red laser light into white light, a remarkable process which is made possible by the high intensity of a pulsed laser beam.”

Wadsworth believes this could be useful in applications where you need to make a laser of several different colours – such as in medical scanners for cancers, or using a confocal microscope in biology.

“This is a unique cross between a light bulb and a laser that simple didn’t exist ten years ago,” Wadsworth said.

The University has just installed a second fibre drawing tower, doubling their capacity to make fibres. The new machine can also use a broader temperature range meaning that the scientists can make finer, more delicate structures using a greater variety of materials.

“Most of the fibres we make here are made of silica based glass. However with our new facility we will be able to investigate a greater range of materials and hopefully discover new applications for the fibres,” said Wadsworth. “Bath is only one of three universities in the UK to have this facility and so this new tower will ensure that we stay at the forefront of photonics research.”