Attosecond Real-Time Observation of Recolliding Electron Trajectories in Helium at Low Laser Intensities

Raman time-delay in attosecond transient absorption of strong-field created krypton vacancy

“…The Wigner time-delay is indeed the other facet of the quantum coherence of the wave packet by which counting the scattering phase variation is meaningful. It can be generalized to other processes whenever a continuum is involved, providing a fresh look at various fundamental processes in time domain, such as tunneling ionization 12 – 14 , photoemission 8 , 9 , Auger decay 15 , electron correlation 16 , AC Stark shift 17 , spin-orbit coupling 1 , electron transportation 18 and recollision dynamics 19 . So far, less attention has been paid to the time-delay of resonant absorption.…”

Plucking an Atom’s Electrons

“…The landmark feat depended on the laser's strong oscillating electric field, which tore away the atoms' valence electrons and hurled them back half a cycle later. Now Tobias Heldt of the Max Planck Institute for Nuclear Physics in Germany and his collaborators have developed a new experimental technique that is, in a sense, a mirror image of the 2003 demonstration: they used attosecond XUV pulses to free the valence electrons and to then track their response to femtosecond NIR laser pulses [1].…”

Symmetries and correlations in solids probed by ultrafast high-harmonic spectroscopy

“…Additionally, noise reduction is possible by referencing, using the laser power [304], the spectral regions unaffected by the pump-induced dynamics [192,305], or a second spectrum of the XUV pulse before the sample [306,307]. It is also possible to use an almost common path referencing by splitting up the XUV beam [308,309,310]. However, these approaches typically impose requirements on the sample and experimental geometry and can not be easily used in a large variety of beam lines.…”