Quantum control of multi-photon dissociation of HCl+ with intense femtosecond laser pulses

The multi-photon dissociation of HCl(+) through three channels HCl(+)→H(1s|(2)S)+Cl(+)((3)P), H(+)+Cl((2)P(0)), and H((2)S)+Cl(+)((1)D) steered by intense femtosecond laser pulses are investigated theoretically using the quantum wave packet dynamics. The numerical calculations are performed in two cases without and with the coupling between the excited states. The results show that the dissociation is sensitive to the duration τ, peak intensity I(0), and the resonance of driving laser fields. In the case without the coupling, the effect of the permanent dipole moments on the dissociations dominates for τ < 15 fs, while with the increase of τ, the dissociation dynamics is mainly dominated by the transition dipole moment. In the case with the coupling, the above-threshold dissociation process is complex, and the non-resonant (λ = 400 nm) and resonant (λ = 800 and 1200 nm) laser fields lead to different variation of the branching ratios. The angle-resolved energy distribution is also discussed in detail.