Logo Logo
Switch Language to German
Bergues, B.; Rivas, D. E.; Weidman, M.; Muschet, A. A.; Helml, Wolfram; Guggenmos, A.; Pervak, V.; Kleineberg, U.; Marcus, G.; Kienberger, R.; Charalambidis, D.; Tzallas, P.; Schröder, H.; Krausz, F.; Veisz, L. (2018): Tabletop nonlinear optics in the 100-eV spectral region. In: Optica, Vol. 5, No. 3: pp. 237-242
Creative Commons Attribution 1MB


Nonlinear light-matter interactions in the extreme ultraviolet (XUV) are a prerequisite to perform XUV-pump/XUV-probe spectroscopy of core electrons. Such interactions are now routinely investigated at free-electron laser (FEL) facilities. Yet, electron dynamics are often too fast to be captured with the femtosecond resolution of state-of-the-art FELs. Attosecond pulses from laser-driven XUV-sources offer the necessary temporal resolution. However, intense attosecond pulses supporting nonlinear processes have only been available for photon energy below 50 eV, precluding XUV-pump/XUV-probe investigation of typical inner-shell processes. Here, we surpass this limitation by demonstrating two-photon absorption from inner electronic shells of xenon at photon energies around 93 eV and 115 eV. This advance opens the door for attosecond real-time observation of nonlinear electron dynamics deep inside atoms.