Structures in molecular photofragment and photoelectron distributions fromtwo-photon non-resonant excitation

We regard molecular two-photon electronic transitions induced by the intera ction of two pulses with different frequencies and temporal widths. Whereas one pulse is tuned off resonance between two vibrational levels in an inte rmediate electronic state the second one induces a transition to a dissocia tive or ionic electronic state. It is shown that in both case the non-reson ant excitation induces structures in the final state distributions which ar e not present for resonant excitation. (C) 1999 Elsevier Science B.V. All r ights reserved.