Intense laser induced electronic excitation in dissociative ionization of ethanol studied by photoelectron-photoion coincidence momentum imaging

Hosaka, Koichi; Itakura, Ryuji; Yokoyama, Keiichi  ; Yamanouchi, Kaoru*; Yokoyama, Atsushi

We have performed photoelectron-photoion coincidence imaging measurements and revealed the correlation between the initially prepared electronic states of parent ions and the subsequent dissociation processes. Comparisons are made among the photoelectron images for the four different single ionization channels; the parent ion formation, H elimination, CH elimination, and OH elimination. At the intensity of 9.3 TW/cm with the duration of 35 fs, the electronically excited states are prepared directly in the ionization for the CH and OH elimination. As the pulse becomes longer and stronger, the ionization to the electronic ground state becomes dominant even for the CH and OH elimination, suggesting the efficient electronic excitation subsequent to the ionization.