title: Mid-infrared ultrafast laser pulses induced third harmonic generation in nitrogen molecules on an excited state.
abstract: We report on generation of third harmonic from nitrogen molecules on the excited state with a weak driver laser pulse at a mid-infrared wavelength. The excited nitrogen molecules are generated using a circularly polarized intense femtosecond pulse which produces energetic electrons by photoionization to realize collisional excitation of nitrogen molecules. Furthermore, since the third harmonic is generated using a pump-probe scheme, it enables investigation of the excited-state dynamics of nitrogen molecules produced under different conditions. We also perform a comparative investigation in excited argon atoms, revealing different decay dynamics of the molecules and atoms from the excited states in femtosecond laser induced filaments.
authors.affiliation: State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Xie
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: Guihua
authors.initials: G
authors.lastname: Li
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.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: Wei
authors.initials: W
authors.lastname: Chu
authors.affiliation: State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.|School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Ziting
authors.initials: Z
authors.lastname: Li
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: Bin
authors.initials: B
authors.lastname: Zeng
authors.affiliation: School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Zhanshan
authors.initials: Z
authors.lastname: Wang
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: Ya
authors.initials: Y
authors.lastname: Cheng