Decoupling structural molecular dynamics from excited state lifetimes using few-femtosecond ultraviolet resonant dispersive waves
Optical sources exploiting resonant dispersive wave (RDW) emission are set to revolutionize ultrafast science. We demonstrate this approach by investigating excited state dynamics in morpholine using time-resolved photoelectron imaging. Excitation at 250 nm was achieved via RDW emission inside a helium-filled capillary fibre which, when combined with a short 800 nm probe, realized an instrument response of just 11 ± 2 fs. Two pathways initiate N-H bond fission: an extremely fast (<10 fs) process and a frustrated mechanism (380 fs) with hindered electronic ground state access. Photoelectron angular distributions also indicate average molecular geometry evolving on an intermediate (~100 fs) timescale. This clean distinction between population lifetimes and structural dynamics is enabled by the excellent temporal resolution inherent in RDW-based sources. Electronic structure and nonadiabatic surface hopping calculations support our data interpretation, and the synergy between experiment and theory is vital for developing a complete mechanistic picture.
Authors
- Lewis Hutton (ORCID: https://orcid.org/0000-0002-7061-5030)
- Chris Sparling (ORCID: https://orcid.org/0000-0001-9720-6766)
- Sebastian L. Jackson (ORCID: https://orcid.org/0000-0001-9889-9891)
- Νικολέτα Κωτσίνα (ORCID: https://orcid.org/0000-0001-6493-3481)
- Andrew W. Prentice (ORCID: https://orcid.org/0000-0002-9740-9093)
- Martin J. Paterson (ORCID: https://orcid.org/0000-0002-0012-974X)
- Adam Kirrander (ORCID: https://orcid.org/0000-0002-3347-8137)
- Christian Brahms (ORCID: https://orcid.org/0000-0002-8009-3547)
- John C. Travers (ORCID: https://orcid.org/0000-0003-0350-9104)
- Dave Townsend (ORCID: https://orcid.org/0000-0002-2522-4655)
- Lauren Bertram (ORCID: https://orcid.org/0000-0002-1503-0902)
Institutions
- Elettra-Sincrotrone Trieste S.C.p.A. (IT)
- Heriot-Watt University (GB)
- University of Oxford (GB)
- Heriot-Watt University Malaysia (MY)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-11-13
- DOI
- https://doi.org/10.1038/s41467-025-64943-5
- Citations
- 1
- Primary Topic
- Laser-Matter Interactions and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.25
Funders
- U.S. Department of Energy
- Heriot-Watt University
- Leverhulme Trust
- Royal Academy of Engineering
- University of Oxford
- European Commission
- Office of Science
- Engineering and Physical Sciences Research Council
- Basic Energy Sciences