title: Spatial evolution of multiple filaments in air induced by femtosecond laser pulses.
abstract: The spatial evolution of plasma filaments in air induced by femtosecond laser pulses is investigated experimentally. Several major filaments and small scaled additional filaments are detected in the plasma channel. The complicated interaction process of filaments as splitting, fusion and spreading is observed. The major filaments propagate stably, and the small scaled additional filaments can be attracted to the major filaments and merged with them. The major filaments are formed due to the perturbation of initial beam profile and the small scaled filaments are mainly caused by the transverse modulational instability.
authors.forename: Zuo-Qiang
authors.initials: ZQ
authors.lastname: Hao
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Xi
authors.forename: Yu-Tong
authors.initials: YT
authors.lastname: Li
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Yuan
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Zheng
authors.forename: Zhao-Hua
authors.initials: ZH
authors.lastname: Wang
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Ling
authors.forename: Zhi-Yi
authors.initials: ZY
authors.lastname: Wei