Excitation dynamics in molecule resolved by internuclear distance driven by the strong laser field

Rydberg-state excitation of stretched model molecules subjected to near-infrared intense laser fields has been investigated based on a fully quantum model (QM) proposed recently and the numerical solutions of time-dependent Schrödinger equation (TDSE). Given the good agreement between QM and TDSE, it is found that, as the molecules are stretched, the electron tends to be trapped into low-lying Rydberg-states after its ionization from the core, which can be attributed to the shift of the ionization moments corresponding to maximum excitation populations. Moreover, the n-distribution is broadened for molecules with increasing internuclear distance, which results from the change of momentum distribution of emitted electrons. Analysis indicates that both of the above phenomena are closely related to the interference effect of electronic wave packets emitted from different nuclei. Our study provides a more comprehensive understanding of the molecular excitation in intense laser fields, as well as a means of possible applications to related experimental observations.