Redirection and reshaping of intense extreme-ultraviolet radiation
- Yu He
- Alexander Magunia
- Harijyoti Mandal
- Muwaffaq Ali Mourtada
- Carlo Kleine
- Arikta Saha
- Marc Rebholz
- Gergana D. Borisova
- Lina Hedewig
- Hannes Lindenblatt
- Florian Trost
- Ulrike Frühling
- Christina C. Papadopoulou
- Elisa Appi
- Stefan Düsterer
- Tino Lang
- Skirmantas Alisauskas
- Christoph M. Heyl
- Steffen Palutke
- Markus Braune
- Christina Bömer
- Dietrich Krebs
- Doriana Vinci
- Philip Mosel
- Peer Biesterfeld
- Ingmar Hartl
- Robert Moshammer
- Milutin Kovacev
- Kiyoshi Ueda
- Mette B. Gaarde
- Christian Ott
- Thomas Pfeifer
2026-05-29
The goal to control short-wavelength radiation for the investigation and manipulation of ultrafast dynamics in quantum systems coevolves with the growing availability of extreme-ultraviolet (XUV) and x-ray sources from high-harmonic generation and free-electron lasers. Here, we present an XUV spatio-spectral phase modulator based on an intense XUV laser beam propagating through an optically thick resonant target, introducing dispersion profile variations around the resonance both perpendicular to and along the laser propagation direction. The resulting dipole radiation gets spectrally reshaped and becomes more divergent as compared to the original beam in the far field. As an experimental demonstration, the intense-XUV–induced double-peak off-axis structure in the far-field spectrum obtained at the Free-Electron Laser in Hamburg (FLASH) shows indications of the underlying XUV-driven Rabi dynamics and resonant pulse propagation effects. The presented work highlights a ubiquitous phenomenon occurring when an intense laser beam passes through a resonant medium.