Retrieving intracycle interference in angle-resolved laser assisted XUV ionization of Ar

M. KUBIN; ARBÓ, D.G.; O. KORNILOV; J. HUMMERT; S. D. LÓPEZ; M. J. J. VRAKKING

Budapest

Conferencia; The International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces; 2018

EKHO' 94 Ltd., Debrecen

Photoelectron spectra have been described in the literature as an interference problem in the time domain. Whereas trajectories stemming from different optical laser cycles give rise to intercycle interference energy peaks known as sidebands, these sidebands are modulated by a coarse grained structure coming from the intracycle interference of the electron trajectories born during the same optical cycle [1,2,3,4].In this work, we show that even in experiments where interferences are missing or hidden by the varying intensities in the focal volume, the intracycle interference evidenced in the modulation of the sidebands emerges when the two angle-resolved and energy-resolved distributions taken at somewhat different laser intensity are subtracted.The experiments presented here are carried out using recently constructed XUV time delay compensating monochromator beamline [4] and a velocity map imaging spectrometer. This system is capable of producing a wavelength-selected, but short XUV pulse and thus is best suitable for studying laser-assisted XUV ionization processes. In the experiments, Atoms are ionized by 29.5 eV photons in the presence of IR field, which leads to generation of several sidebands.