Single-order laser high harmonics in XUV for ultrafast photoelectron spectroscopy of molecular wavepacket dynamics

Abstract

We present applications of extreme ultraviolet (XUV) single-order laser harmonics to gas-phase ultrafast photoelectron spectroscopy. Ultrashort XUV pulses at 80 nm are obtained as the 5th order harmonics of the fundamental laser at 400 nm by using Xe or Kr as the nonlinear medium and separated from other harmonic orders by using an indium foil. The single-order laser harmonics is applied for real-time probing of vibrational wavepacket dynamics of I2 molecules in the bound and dissociating low-lying electronic states and electronic-vibrational wavepacket dynamics of highly excited Rydberg N2 molecules.

Suppression of individual peaks in two-colour high harmonic generation

“…The demonstrated additional control parameter of halfcycle asymmetry will eventually be useful in optimising waveforms to generate a desired spectral modulation as have been performed for optimizing yield and cutoff energies [13,38,39]. It is expected to greatly bene t applications demanding further tunability of HHG, like in molecular spectroscopy or measurement of atomic transition lines with XUV frequency combs [40,41].…”

Photoelectron spectroscopy of Rydberg excited states in singly charged molecular ions CS2 + by NIR laser pulses

“…Although the present study was limited to the fixed time-delay between the XUV pump and the NIR probe pulses, the experimental scheme is naturally extendable to the time-dependent measurements. By using a highly coherent XUV-FEL pump pulse (such high coherence would be realized by a seeding technique), the real-time observation of electronic-vibrational wavepacket dynamics will be also possible for highly excited Rydberg states of molecular ions (on neutral molecules, for example, [32][33][34][35]).…”