Dynamical quenching of laser-induced dissociations of diatomic molecules in intense infrared fields: Effects of molecular rotations and misalignments

The dynamical dissociation quenching (DDQ) effect is a new mechanism for laser-induced vibrational trapping of molecules in the infrared (IR) spectral range. Previously demonstrated for one-dimensional, prealigned diatomic molecules [see F. Châteauneuf, T. Nguyen-Dang, N. Ouellet, and O. Atabek, J. Chem. Phys. 108, 3974 (1998)], the effect was shown to result from a proper synchronization of the molecular motions with the oscillations of the laser electric field. The present paper explores the influence of rotations and misalignment of the molecular system on the DDQ effect. To this end, the two-dimensional (radial and angular) wave-packet dynamics of the H2+ and HD+ molecular ions are considered in an intense IR laser field starting from two types of initial angular distributions: The first type of distributions is appropriate for a field-free, pure angular momentum eigenstate and denotes typically an initially nonaligned, nonoriented molecule. The second type denotes a more or less well aligned and/or o...