Laser-induced alignment dynamics of HCN: Roles of the permanent dipole moment and the polarizability
Claude M. Dion1,2, Arne Keller1, Osman Atabek1,
and André D. Bandrauk2
1Laboratoire de Photophysique Moléculaire
du CNRS, Université Paris-Sud, Bâtiment 213, 91405 Orsay,
France
2Laboratoire de Chimie Théorique,
Faculté des Sciences, Université de Sherbrooke, Sherbrooke,
Québec, Canada J1K 2R1
The alignment dynamics of HCN, in a linear configuration, interacting with linearly polarized infrared laser pulses are studied numerically by exact (nonperturbative) solutions of the time-dependent Schrödinger equation. The alignment, with respect to the laser field polarization vector, is measured from the angular distribution of the molecule using a defined half angle theta1/2. It is shown that, at intensities I = 1013 W/cm2, alignment can be achieved on a subpicosecond time scale with a single laser frequency, in the presence of simultaneous dipole- and polarizability-field interactions. The results are compared to those of a laser-driven rigid-rotor analytical model that is thoroughly developed. The importance of the permanent and field-induced dipole moments on the alignment process is investigated, as well as the role of vibrational excitation of the two molecular bonds.
This article appeared in The Physical Review A 59, 1382 (1999) and may be found at http://publish.aps.org/abstract/PRA/v59/p1382.
Back to list of publications.