@article{JurkovičovaBenLtaiefRoosetal.2024, author = {Jurkovičov{\´a}, Lucie and Ben Ltaief, Ltaief and Roos, Andreas Hult and Hort, Ondřej and Finke, Ondřej and Albrecht, Martin and Hoque, Ziaul and Klimešov{\´a}, Eva and Sundaralingam, Akgash and Antipenkov, Roman and Grenfell, Annika and Špaček, Alexandr and Szuba, Wojciech and Krikunova, Maria and Mudrich, Marcel and Nejdl, Jaroslav and Andreasson, Jakob}, title = {Bright continuously tunable vacuum ultraviolet source for ultrafast spectroscopy}, series = {Communications Physics}, volume = {7}, journal = {Communications Physics}, publisher = {Nature Publishing Group}, issn = {2399-3650}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18462}, year = {2024}, abstract = {Ultrafast electron dynamics drive phenomena such as photochemical reactions, catalysis, and light harvesting. To capture such dynamics in real-time, femtosecond to attosecond light sources are extensively used. However, an exact match between the excitation photon energy and a characteristic resonance is crucial. High-harmonic generation sources are advantageous in terms of pulse duration but limited in spectral tunability in the vacuum ultraviolet range. Here, we present a monochromatic femtosecond source continuously tunable around 21eV photon energy utilizing the second harmonic of an optical parametric chirped pulse amplification laser system to drive high-harmonic generation. The unique tunability of the source is verified in an experiment probing the interatomic Coulombic decay in doped He nanodroplets across the He absorption bands. Moreover, we achieved intensities sufficient for driving collective processes in multiply excited helium nanodroplets, which have been previously observed only at free electron lasers.}, language = {en} }