Laboratory of Ultrafast Spectroscopy LSU

Ultrafast spectroscopy with femtosecond laser and fs/ps X-ray pulses – Condensed-phase dynamics – Dynamics of Biomolecules – Photovoltaic Materials

Welcome to Laboratory of Ultrafast Spectroscopy LSU

The activities of our laboratory aim at a detailed description of photo-induced processes in the molecular condensed phase (liquid, solid and proteins) and in metallic and semiconductor nanostructured materials. A central approach of our group is the visualization in “real time” of the processes by means of ultrafast laser spectroscopy.
The physical phenomena we investigate include: structural changes in the chromophores and the medium (be it a solvent or a protein) and the influence of local electric fields on their spectral and dynamical features. We also study the ultrafast dynamics of charge carriers in semiconductor and metallic nanostructures of different shapes and sizes.
The experimental tools we use are ultrafast picosecond and femtosecond transient absorption spectroscopy, ultrafast fluorescence up-conversion spectroscopy, photon-echo spectroscopy. We have also developed novel optical laser pump-X-ray probe techniques using femtosecond and femtosecond hard X-ray pulses from a synchrotron.


Artist's impression of a time-resolved circular dichroism measurement of a photoexcited spin-crossover complex. Credit: Ella Maru Studio, Inc.

Tracking chirality in real time

— Scientists at EPFL have developed a new laser-based technique that can measure ultrafast changes in the structural symmetry of molecules, called chirality, tracking their conformational shifts in real time. In a collaboration with researchers from the Universities of Geneva and Pisa, the breakthrough resolves a long-standing issue on how an important class of metal complexes switch their magnetic properties when triggered by a flash of light, and can have implications for magnetic data storage applications.

© 2022 EPFL

Jérémy Rouxel wins the FELs of Europe Award 2022

— 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.

© 2022 EPFL

ICO/IUPAP Young Scientist Prize in Optics 2021 to Giulia F. Mancini

— Giulia Fulvia Mancini wins the 2021 Young Scientist Prize in Optics for her “contributions to imaging and scattering of nanostructured materials using high- harmonic soft X-ray sources and research on extreme ultraviolet imaging"

© 2021 EPFL

The 2021 Ernst Haage Award to Rebeca Gomez Castillo

— Ernst Haage PhD Award 2021 for outstanding research achievements in chemistry

Majed Chergui. Credit: EPFL

Majed Chergui elected Fellow of the European Academy of Sciences

— EPFL Professor and founding director of the Lausanne Centre for Ultrafast Science (LACUS), Majed Chergui, has been elected Fellow of the European Academy of Sciences.

Professors Mazzanti, Chergui, Aye, and Queen. Credit: EPFL

ACS awards and honors for EPFL scientists

— Four scientists from EPFL’s Institute of Chemical Sciences and Engineering have won awards and honors from the American Chemical Society.

Anatomy of the Eye, authored by al-Mutadibih © the Cairo National Library

Optics and Arabic science EPN2020

— Arabic science of light: The birth of modern optics and of the experimental method

© 2020 EPFL

2020 PHYS Division Young Investigator Awards

— Edoardo was awarded another prize, this time for the ACS, entirely based on his thesis work on TiO2.

© 2020 EPFL

New quasiparticle unveiled in room temperature semiconductors

— Physicists from Switzerland and Germany have unveiled fingerprints of the long-sought particle known as Mahan exciton in the room temperature optical response of the popular methylammonium lead halide perovskites.

© 2020 EPFL

International Workshop "Electrons, Photons and Plasmons-2020"

— Save the date : June 3-5 2020, Nyon, Switzerland