title: Realizing Ultrafast Electron Pulse Self-Compression by Femtosecond Pulse Shaping Technique.
abstract: Uncorrelated position and velocity distribution of the electron bunch at the photocathode from the residual energy greatly limit the transverse coherent length and the recompression ability. Here we first propose a femtosecond pulse-shaping method to realize the electron pulse self-compression in ultrafast electron diffraction system based on a point-to-point space-charge model. The positively chirped femtosecond laser pulse can correspondingly create the positively chirped electron bunch at the photocathode (such as metal-insulator heterojunction), and such a shaped electron pulse can realize the self-compression in the subsequent propagation process. The greatest advantage for our proposed scheme is that no additional components are introduced into the ultrafast electron diffraction system, which therefore does not affect the electron bunch shape. More importantly, this scheme can break the limitation that the electron pulse via postphotocathode static compression schemes is not shorter than the excitation laser pulse due to the uncorrelated position and velocity distribution of the initial electron bunch.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Yingpeng
authors.initials: Y
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Minjie
authors.initials: M
authors.lastname: Pei
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Dalong
authors.initials: D
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Tianqing
authors.initials: T
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.|NYU-ECNU Institute of Physics at NYU Shanghai , 3663 North Zhongshan Road, Shanghai, 200062, China.
authors.forename: Shian
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Zhenrong
authors.initials: Z
authors.lastname: Sun
keywords: electron pulse self-compression; femtosecond pulse shaping; ultrafast electron diffraction