Orientation of linear molecules in two-color laser fields with perpendicularly crossed polarizations

Abstract

Molecular orientation methods based on nonresonant two-color laser pulses having parallel polarizations have been reported theoretically and experimentally. In this work, we demonstrate that perpendicularly polarized two-color laser fields can be used to achieve stronger molecular orientation when nanosecond laser pulses are used. The two-color fields align the molecules to the two-dimensional plane parallel to the field polarization; at the same time, they orient the molecules in the direction of the $2\ensuremath{\omega}$ polarization. We show that the interplay between the interactions due to the $\ensuremath{\omega}$- and $2\ensuremath{\omega}$-laser fields provides stronger molecular orientation than the parallel field configuration. This is due to temporally synchronized generations of alignment and orientation, which reduce the nonadiabatic effects.