Time-frequency representation of autoionization dynamics in helium

Research output: Contribution to journalArticle


Autoionization, which results from the interference between direct photoionization and photoexcitation to a discrete state decaying to the continuum by configuration interaction, is a well known example of the important role of electron correlation in light-matter interaction. Information on this process can be obtained by studying the spectral, or equivalently, temporal complex amplitude of the ionized electron wave packet. Using an energy-resolved interferometric technique, we measure the spectral amplitude and phase of autoionized wave packets emitted via the sp2+ and sp3+ resonances in helium. These measurements allow us to reconstruct the corresponding temporal profiles by Fourier transform. In addition, applying various time-frequency representations, we observe the build-up of the wave packets in the continuum, monitor the instantaneous frequencies emitted at any time and disentangle the dynamics of the direct and resonant ionization channels.


External organisations
  • University of Paris-Saclay
  • University of Gothenburg
  • Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy
  • Autonomous University of Madrid
  • IMDEA Nanociencia
  • University of Central Florida
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics


  • attosecond pulse, autoionization, Fano resonance, RABBIT, time-frequency representations, Wigner
Original languageEnglish
Article number044002
JournalJournal of Physics B: Atomic, Molecular and Optical Physics
Issue number4
Publication statusPublished - 2018 Jan 23
Publication categoryResearch