title: Terahertz-induced field-free orientation of rotationally excited molecules.
abstract: We have used picosecond THz pulses to induce transient field-free orientation of OCS molecules. Coherent optical Raman excitation prepares the molecules in rotational superposition states prior to THz irradiation, substantially enhancing the degree of orientation. The time-dependent alignment and orientation are characterized via Coulomb explosion in an intense probe laser. The degree of OCS orientation is an order of magnitude larger than previously observed following THz irradiation and is achieved with a significantly smaller THz field.The field-free orientation level is comparable to that generated using pulsed, two-color laser fields but is obtained with negligible target ionization.
authors.affiliation: Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714, USA.
authors.forename: K N
authors.initials: KN
authors.lastname: Egodapitiya
authors.affiliation: Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714, USA.
authors.forename: Sha
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Jones