Attosecond time-energy structure of X-ray free-electron laser pulses

Hartmann, N.; Hartmann, G.; Heider, R.; Wagner, M. S.; Ilchen, M.; BucK, J.; Lindahl, A. O.; Benko, C.; Gruenert, J.; Krzywinski, J.; Liu, J.; Lutman, A. A.; Marinelli, A.; Maxwell, T.; Miahnahri, A. A.; Möller, S. P.; Planas, M.; Robinson, J.; Kazansky, A. K.; Kabachnik, N. M.; Viefhaus, J.; Feurer, T.; Kienberger, R.; Coffee, R. N. und Helml, W. (2018): Attosecond time-energy structure of X-ray free-electron laser pulses. In: Nature Photonics, Bd. 12, Nr. 4: S. 215-220

Abstract

The time-energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modulations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 1749-4885
• Sprache: Englisch