Abstract

We introduce a new tool to control the nonadiabatic alignment dynamics in asymmetric top molecules. Alignment is induced using nonresonant, linearly polarized laser pulses with pulse durations that are short compared to the rotational periods of the molecule. Through a series of nonresonant Raman transitions a rotational wave packet is created. The temporal evolution of the wave packet is determined by the field free energy eigenstates populated in the molecule, thus alignment results from interference among the eigenstates forming the rotational wave packet. Alignment occurs shortly after the laser pulse and at subsequent wave packet revivals as the most polarizable molecular axis aligns along the polarization direction of the laser field. For linear and symmetric top molecules the revival pattern is periodic Asymmetric top molecules, however, display much more interesting rotational dynamics. We demonstrate an interesting dependence of the rotational wave packet dynamics of asymmetric tops on the pulse duration of the alignment pulse, effectively converting the complex, non-periodic rotations of an asymmetric top into the simple periodic pattern characteristic of symmetric tops.

© 2007 IEEE