Jérémy Rouxel wins the FELs of Europe Award 2022
© 2022 EPFL
During his work at EPFL Jérémy Rouxel contributed to the first demonstration of ultrafast hard X-ray transient grating spectroscopy. The extension of this methods to this photon energy range, recently available at the hard X-ray free electron lasers such as SwissFEL, will provide a unique microscopic tool to address for the first time transport phenomena at the nanoscale in materials with element-selectivity.
Jérémy Rouxel joined the LSU group at EPFL after his postdoc in the Mukamel group at University of California at Irvine. During his time at EPFL Jérémy contributed to demonstrate transient grating spectroscopy in the hard X-ray range for the first time. This is an important development in the field of non-linear optics and spectroscopy in the X-ray range. The advantage of the hard X-Ray range is the combination of chemical specificity with the short wavelengths ensuring access to nanoscale transient gratings, which opens the way to the study of transport phenomena either at the nanoscale in solid and liquid materials, or of transport within nanostructures. Transient grating is achieved by crossing two identical laser beams on the sample, thus forming an interference pattern of excitation (be it electronic, thermal or magnetic) in the sample. The challenge in the hard X-ray is to achieve crossing the two beams due the lack of optical elements in this range. This was overcome by Jérémy and his main collaborator Cris Svetina at the Paul-Scherrer-Institut, by a clever solution based on the Talbot effect (*see publication). For this achievement, Jérémy receive the prize FELs of Europe Award 2022 for the “Development or innovative use of advanced instrumentation in the field of FELs” for young researchers . Currently Jérémy is assistant professor at the Université de Saint-Etienne in France.