Resonance effects in two-photon double ionization of H2by femtosecond XUV laser pulses

Abstract

We investigate the effect of the pulse length on the two-photon double ionization (DI) of H 2 in the direct domain, for a femtosecond (fs) laser with a polarization vector oriented along the molecular axis. In the fixednuclei approximation, we find that the doubly excited Q 1 1 + u states manifest themselves as resonances in the angle-integrated cross sections if the laser interaction lasts longer than about 3 fs. Decay into single-ionization channels does not significantly affect the shape of the angular distribution. A sharp rise in the probability for DI, due to virtual sequential ionization, occurs when the photon energy approaches the threshold for sequential DI.

Enhanced ionization of vibrational hot carbon disulfide molecules in strong femtosecond laser fields

“…[10] The pronounced R-dependent ionization could be used as an interesting method of forming the coherent vibrational wavepackets in ground electronic states with strong laser fields. [11][12][13] Theoretical studies have predicted that for some diatomic molecules such as N 2 [14] and H 2 , [15] the HHG efficiency could be improved significantly by vibrational motion, which is also attributed to the enhanced ionization. Furthermore, by numerically solving the time-dependent Schrödinger equation for H + 2 , Kästneret et al have shown that the ionization and dissociation channels of the molecule could be steered if the molecule is prepared in a specific vibrational state.…”

Two-photon double ionization of metastable1,3S1s2shelium

“…Being the simplest two-electron system, * aleksander.simonsen@ift.uib.no † morten.forre@ift.uib.no helium was the first target of considerable theoretical [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and experimental [26][27][28][29][30][31] interest. Other two-electron systems have also been investigated, including TPDI of fixed-in-space H 2 [32][33][34][35][36][37][38].…”