Determining laser-induced dissociation pathways of multielectron diatomic molecules: Application to the dissociation ofO2+by high-intensity ultrashort pulses

Abstract

A method for determining the laser-induced dissociation pathways of multielectron diatomic molecules is developed. Despite the abundance of possible dissociation pathways inherent to such molecules, this technique allows one to resolve the dissociation pathways that contribute to the measured intensity-dependent threedimensional momentum distribution. To illustrate this method, the unique dissociation mechanisms and pathways producing a few predominant features in the laser-induced dissociation momentum distribution of O 2 + are determined.

Tracking nuclear wave-packet dynamics in molecular oxygen ions with few-cycle infrared laser pulses

“…1(a), corresponding to a KER of less than 2 eV, result from the dissociation of O 2 + into O + and O fragments. Some of the low-energy features seen here were previously reported by Sayler et al [8]. The ring with momenta near 100 a.u.…”

Incorporating real time velocity map image reconstruction into closed-loop coherent control

“…Strong-field ionization of O 2 leads to a number of dissociation pathways [55][56][57]60 as shown by the data in Fig. 4.…”

“…4, gates can be defined by radius and angle directly on the 3D-VMI itself. This is a good choice if [55][56][57] The laser polarization direction is vertical. The gate settings for this experiment, discussed in Sec.…”

“…While this is most likely the dominant pathway at this KER value, the |a 4 u → |f 4 g − 1ω bond-softening pathway should contribute a broad KER tail in this region. 55,56,60 Other pathways, such as |X u − 2ω pathway is expected to have a cos 2 (θ )sin 2 (θ ) angular distribution, 55,56,60 while the other pathways mentioned above should have angular distributions characterized by cos 2 (θ ) to cos 10 (θ ) depending on the number of photons involved.…”

“…6(a), following ionization of O 2 to the a 55,56 to O + + O leading to a KER peak of around 1.5 eV. This "double bond-softening" pathway has a complex angular structure 55 that includes both parallel (with the lasermolecule interaction depending on the laser field strength parallel to the internuclear axis since there is no change, = 0, in the angular momentum quantum number) and perpendicular ( = ±1, depending on the laser field strength perpendicular to the internuclear axis) transitions. While this is most likely the dominant pathway at this KER value, the |a 4 u → |f 4 g − 1ω bond-softening pathway should contribute a broad KER tail in this region.…”