title: Alignment-dependent fluorescence emission induced by tunnel ionization of carbon dioxide from lower-lying orbitals.
abstract: The study of the ionization process of molecules in an intense infrared laser field is of paramount interest in strong-field physics and constitutes the foundation of imaging of molecular valence orbitals and attosecond science. We show measurement of alignment-dependent ionization probabilities of the lower-lying orbitals of the molecules by experimentally detecting the alignment dependence of fluorescence emission from tunnel ionized carbon dioxide molecules. The experimental measurements are compared with the theoretical calculations of the strong field approximation and molecular Ammosov-Delone-Krainov models. Our results demonstrate the feasibility of an all-optical approach for probing the ionization dynamics of lower-lying orbitals of molecules, which is until now still difficult to achieve by other techniques. Moreover, the deviation between the experimental and theoretical results indicates the incompleteness of current theoretical models for describing strong field ionization of molecules.
authors.affiliation: State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Yao
authors.forename: Guihua
authors.initials: G
authors.lastname: Li
authors.forename: Xinyan
authors.initials: X
authors.lastname: Jia
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Hao
authors.forename: Bin
authors.initials: B
authors.lastname: Zeng
authors.forename: Chenrui
authors.initials: C
authors.lastname: Jing
authors.forename: Wei
authors.initials: W
authors.lastname: Chu
authors.forename: Jielei
authors.initials: J
authors.lastname: Ni
authors.forename: Haisu
authors.initials: H
authors.lastname: Zhang
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Xie
authors.forename: Chaojin
authors.initials: C
authors.lastname: Zhang
authors.forename: Zengxiu
authors.initials: Z
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Liu
authors.forename: Ya
authors.initials: Y
authors.lastname: Cheng
authors.forename: Zhizhan
authors.initials: Z
authors.lastname: Xu