title: Ellipticity dependence of high-order harmonic generation from aligned molecules.
abstract: We report ellipticity dependence of high-order harmonic generation (HHG) from aligned N2, O2, and CO2 molecules. Experimentally, we find that the ellipticity dependence is sensitive to molecular alignment and to the shape and symmetry of the valence orbitals. It is also found that the destructive interference in the recombination process affects the ellipticity dependence. Theoretically, we extend the original Lewenstein model to a more generalized model, which can be applicable to HHG from molecules, by introducing an electron acceleration parameter xi(theta) and by combining the molecular orbital method. The present observations are successfully explained by our model.
authors.affiliation: Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. tkanai@riken.jp
authors.forename: Tsuneto
authors.initials: T
authors.lastname: Kanai
authors.forename: Shinichirou
authors.initials: S
authors.lastname: Minemoto
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sakai