Environmental sense.

A new class of optical fibre has the potential to improve surgical and medical lasers as well as applications in environmental sensing.

Scientists from the ORC worked with Penn State University (PSU) to pioneer the first optical fibre made with a core of zinc selenide, which is a transparent, yellow-coloured semiconductor, with a very wide transparency range from the visible to beyond 15 microns in the infrared. This new class of optical fibre allows for effective manipulation of infrared light and promises to open the door to more versatile laser technology.

John Badding, Professor of Chemistry at PSU, which led the research, observed: “We’ve known for a long time that zinc selenide is a useful compound, capable of manipulating light in ways that silica can’t. The trick was to get this compound into a fibre structure, something that had never been done before.”

Using an innovative high-pressure chemical deposition technique developed at PSU, the team put zinc selenide inside silica glass capillaries to form the new optical fibres. The high-pressure deposition is unique in allowing formation of such long, thin zinc selenide fibre cores in a very confined space. The new fibres, which were optically characterised at the ORC, have been found to be efficient at converting light from one colour to another using  process called nonlinear frequency conversion, which provides versatility in the visible spectrum and in the infrared. Exploiting this new fibre core material represents a step towards making novel infrared lasers.

“In particular, the fibre format allows for very robust, compact and rugged solid-state laser systems with inherent high-performance characteristics,” explains Anna Peacock, a Royal Academy of Engineering Research Fellow at the ORC, one of the three Southampton scientists involved with the research, along with Noel Healy and Senior Research Fellow Pier Sazio. Pier added: “Other applications for these fibres include the detection of pollutants and environmental toxins, and they may also open new avenues of research that could improve laser-assisted surgical techniques, such as corrective eye surgery.”

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