First attosecond pulse control by multilayer mirrors above 100 eV photon energy

Multilayer XUV mirrors serve as key components in the generation of the attosecond pulses from high harmonic radiation1. Those pulses pave the way to investigation of dynamics of electronic motion in atoms, molecules and nanostructures with a never before achieved precision and thus allow to draw conclusions on the basic underlying physics2, 3. Each experiment requires its perfectly tailored attosecond XUV pulse, fully optimized to perfectly match the experimental requirements as spectral resolution with sufficient signal to noise, temporal resolution and chirp. Until recently, experiments were limited to photon energies below 100 eV due to the available HH intensities as well as X-ray optics. Here, we have performed for the first time characterization of single isolated attosecond pulses at about 130 eV by attosecond electron streaking measurements and applied these pulse to photoionization experiments in Xe atoms. In order to achieve improved spectral resolution and high time resolution simultaneously, as is required for comparing attosecond electron dynamics of two adjacent electronic states, we have spectrally cleaned the attosecond pulse by suppressing unwanted ``out-of band'' radiation by improved a-periodic multilayer technology, resulting in an improved signal-to noise ratio for time-resolved electron spectroscopy experiments. This opens the way to study electron dynamics of energetically adjacent electronic states with a temporal resolution which is well below the attosecond pulse length itself4.