Practical high-brightness far-ultraviolet light sources


Practical high-brightness far-ultraviolet light sources

Thu, 09/03/2023 - 13:00 to 14:00


Prof John Travers
Heriot Watt

Heriot-Watt's very own Professor John Travers was recently awarded the Institute of Engineering and Technology AF Harvey Research Prize and will give a lecture about his work on "Practical high-brightness far-ultraviolet light sources" to the IET at 1pm on March 9th. This lecture is available to watch online ( - registration required), however we also plan to live stream the lecture in JW1. This event is open to all IPAQS members and Physics students who are able to attend.

Laser light can be focused to extremely small areas of high intensity, offering ultimate spatial resolution when both measuring and altering matter. Lasers can also produce light pulses with a duration short enough to stroboscopically capture the fastest processes occurring in nature, enabling us to better understand their dynamics.

Combined, these features have made laser sources indispensable to both fundamental science and wide-ranging applications in industry and engineering. From healthcare to manufacturing, semiconductor technology to telecommunications, light emitted by lasers is an essential, often a foundational, component of critical instruments and techniques.

Many of these areas would benefit from a practical and high-brightness laser light source in the deep and vacuum ultraviolet spectral regions, collectively referred to as the far-ultraviolet, and span wavelengths from 50 nm to 300 nm. Far-ultraviolet light is especially important as it is quickly absorbed by all atoms and molecules, making it the ideal tool to probe and process virtually any material with extreme precision.

Existing light source technologies in this region either have very poor spatial quality (excimer lasers, discharge lamps), have very low efficiency or lifetime (conventional nonlinear optics) or require extremely large and expensive building-scale facilities (synchrotrons). None of these offer a practical source to enable a new generation of precision applications of light in the far ultraviolet.

Together with my research group, I have pioneered a new technique to generate pulses of far-ultraviolet light, based on the use of soliton dynamics in gas-filled waveguides, which outperforms all previous techniques. We can generate tuneable, highly focusable, extremely intense, and extremely short pulses of far-ultraviolet light in a compact table-top system that exceeds the capabilities even of building-scale facilities.

I will explain this technique and what we have achieved so far. I will then examine how we plan to scale it both upwards, to achieve extreme pulses of light to probe new fundamental physics, and downwards, to develop photonic-chip-sized devices that can enable new applications essential to the health and wellbeing of society.


John C. Travers is Professor of Physics at Heriot-Watt University, Edinburgh, and Director of the Laboratory of Ultrafast Physics and Optics. He creates new light sources with tailored, and often extreme, properties, and has made multiple significant contributions to ultrafast nonlinear optics.

He is recognised as a pioneer of using gas-filled hollow waveguides for ultrafast frequency conversion, pulse compression and supercontinuum generation, and invented the technique to produce the brightest tuneable source of few-femtosecond vacuum-ultraviolet light pulses worldwide: a foundational technology. The light sources Professor Travers develops range from very small - for advanced industrial applications in the semiconductor industry and healthcare - to very large installations at facilities for fundamental science.

Professor Travers received the MSci degree in Mathematics and Physics from Durham University, UK, in 2003 and the MSc and PhD degrees from Imperial College London (UK) in 2004 and 2008. He was an Imperial College Junior Research Fellow from 2009-2010, after which he moved to the Max Planck Institute for the Science of Light in Erlangen, Germany, as a research group leader.

In 2015 he was awarded the prestigious European Research Council (ERC) Starting Grant and established his research group within the Institute of Photonics and Quantum Science at Heriot-Watt University, in 2016. He was promoted to full Professor of Physics in 2019 and awarded the ERC Consolidator Grant and elected Fellow of Optica in 2020.

The outcomes of his research have been published in over 200 scientific articles, presented in over 100 invited talks, and received attention in a wide range of scientific news outlets.