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Research group

Ultrafast X-ray Group

X-ray microscope image of a bundle of dendrites grown from a mouse neuron. The magnification is higher than possible using visible light.

Our group uses high-intensity femtosecond lasers to generate very short (attosecond) pulses of coherent extreme ultraviolet (XUV) and soft X-ray radiation. This radiation can be used for imaging and spectroscopy at very small dimensions (<50nm) and at very fast timescales (<10fs).


The Ultrafast X-ray group works on the generation and uses of extreme ultraviolet (XUV) and soft X-ray radiation using high energy femtosecond laser pulses. The X-rays are produced using high harmonic generation (HHG), a process which uses electron ejection and recombination to produce very short (attosecond) pulses of light. 

Soft X-ray radiation has many important uses. Its short wavelength makes it ideal for high-resolution microscopy. Many chemicals have absorption edges in the soft X-ray region, making it an important area for spectroscopy. 
Finally, the time resolution available from the generated pulses gives us the overall possibility of femtosecond time resolution and nanometre spatial resolution within the same instrument, which opens whole areas of exciting new science. 

The research effort in this area is multi-disciplinary. Within the ORC we collaborate with Dr Peter Horak, an expert in nonlinear optics. The group has strong collaborations with the School of Chemistry (Prof Jeremy Frey, Dr. Russell Minns), where X-ray scattering using more traditional sources is a long-standing and prestigious research area (the National Centre for X-ray crystallography is based in Southampton Chemistry). More recently, we are building collaborations with the Institute for Life Sciences in biological imaging (John Chad, Katrin Deinhart), and the Rosalind Franklin Institute.  

Key to the process of soft X-ray microscopy with HHG sources is the use of phase retrieval techniques. These are computer algorithms that allow us to generate an image without the use of an objective lens. The scattered light from the illuminated object is collected, and the phase information necessary to recreate an image of the object, lost during the collection process, is recreated using an iterative algorithm. These algorithms can now be combined with machine learning to create new imaging techniques on the nanoscale.  

People, projects, publications and PhDs


Dr Bill Brocklesby

Associate Professor

Research interests

  • Novel imaging & microscopy techniques in the visible and XUV spectral regions;
  • Coherent diffractive imaging of nanoscale systems using XUV radiation generated by high-power ultrashort pulse lasers;
  • Large-scale beam combination;


Address: B46, West Highfield Campus, University Road, SO17 1BJ

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Please email your enquires to Associate Professor Bill Brocklesby.

Optoelectronics Research Centre 
University of Southampton  
SO17 1BJ