Collect. Czech. Chem. Commun. 2001, 66, 991-1004

Recurring Molecular Alignment Induced by Pulsed Nonresonant Laser Fields

Long Cai and Břetislav Friedrich*

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, U.S.A.


We examine the rotational wavepackets created by the nonadiabatic interaction of a linear molecule with a pulsed nonresonant laser field. We map out the recurrences of the wavepackets and of the concomitant alignment as a function of the duration and intensity of the laser pulse. We derive an analytic solution to the time-dependent Schrödinger equation in the short-pulse limit and find it to agree quantitatively with our numerical computations. This indicates that the recurrences are favored under an impulsive transfer of action from the radiative field to the molecule. The recurring wavepackets afford field-free alignment of the molecular axis.

Keywords: Nonresonant induced dipole interaction; Polarizability anisotropy; Hybridization of rotational states; Pulsed laser fields; Alignment of molecular axis; Recurrences; Wave functions; Schrödinger equation; Quantum chemistry.

References: 15 live references.