Congratulations to Marco Dassie! Together with his colleagues from the ATTO2.0-team and the University of Lille, he has successfully compressed 28 fs laser pulses by a factor of 50 in time, generating attosecond pulses in the visible and deep-ultraviolet (DUV) spectrum – all using just a single optical fiber. Inside the gas-filled capillary, the initial near-infrared (NIR) pulses undergo self-compression and blue-shift through soliton-dynamics.
The great potential of this approach lies in the setup’s simplicity: “Attosecond pulses are now easily accessible in any lab that has an amplified commercial femtosecond source,” Marco explains. “Especially in the visible and deep-UV spectrum, this opens exciting opportunities to study the dynamics of valence electrons with minimal technical effort.”
Valence electrons govern the chemical behavior of atoms and molecules - yet a large portion of their ultrafast dynamics has long been out of reach for attosecond techniques. Until last year’s pioneering work by Amelie Heinzerling et al. attosecond pulses in the visible and deep-UV remained elusive. Now, this simpler, single-fiber-based approach, demonstrated by Marco and his colleagues, could bring the tools of attosecond science to a broader research community.
For the first time, the researchers also resolved the electric field waveform of the compressed pulses at the edge of the extreme ultraviolet (XUV) – down to 120 nm – using nonlinear photoconductive sampling. The measured waveforms remained reproducible over a period of three weeks up to the experimental noise level – despite possible changes in the laser parameters or environmental conditions during that time. This underscores the robustness of the method and points to its maturity for practical application in attosecond experiments.
Picture: Thorsten Naeser
Original Publication:
Self-referenced sampling of attosecond visible-vacuum ultraviolet electric fields
M. Dassie, D. Kim, F. Tani, M. Agarwal, M. Mamaikin, N. Karpowicz
Journal of Physics: Photonics 8, 015068 (2026)
