文献类型：期刊文献

英文题名：Collisional dynamics in laser-induced plasmas: evidence for electron-impact excitation

作者：Zhang, Liying[1,2];Wei, Pengfei[2,3];Qin, Meiyan[4];Yuan, Xiaolong[3];Liu, Candong[3];Geng, Tao[1];Zhu, Haiyong[5];Duan, Yanmin[5];Zhuang, Songlin[1];Lu, Peixiang[4];Kim, Dong Eon[6]

机构：[1]Univ Shanghai Sci & Technol, Shanghai Key Lab Modern Opt Syst, Shanghai 200093, Peoples R China;[2]Shaoxing Univ, Dept Phys, Shaoxing 312000, Peoples R China;[3]Chinese Acad Sci, State Key Lab High Field Laser Phys, Shanghai Inst Opt & Fine Mech, Shanghai 201800, Peoples R China;[4]Wuhan Inst Technol, Lab Opt Informat Technol, Wuhan 430205, Hubei, Peoples R China;[5]Wenzhou Univ, Coll Math Phys & Elect Informat Engn, Wenzhou 325035, Peoples R China;[6]POSTECH, Dept Phys, Ctr Attosecond Sci & Technol, Pohang 37673, South Korea

年份：2018

卷号：26

期号：8

起止页码：10392

外文期刊名：OPTICS EXPRESS

收录：SCI-EXPANDED(收录号：WOS:000430337700087)、、EI(收录号：20181705039077)、Scopus(收录号：2-s2.0-85045580993)、WOS

基金：National Natural Science Foundation of China (NSFC) (11474223, 11234004, 61504082, 11604248); Global Research Laboratory Program (2009-00439); Max Planck POSTECH/KOREA Research Initiative Program (2016K1A4A4A01922028).

语种：英文

外文关键词：Electrons - Impact ionization - Laser excitation - Laser produced plasmas - Optical pumping

外文摘要：We have experimentally investigated the collisional dynamics in femtosecond-laser-induced plasmas and presented the evidence for electron-impact excitation through enhanced high-order harmonic (HH) generation. The measurements were carried out by using an elliptically polarized pump pulse to induce the underdense plasmas and by using a time delayed linearly polarized probe pulse to drive the HH generation from the plasmas. We found that the rise time of this enhanced HH generation was insensitive to the ellipticity degree (ED) of pump pulse but sensitive to its laser intensity (LI). With further comparison between physical scenarios and qualitative analysis, we demonstrated that the atomic excitation causing the HH enhancement should be attributed to the electron-impact excitation. i.e., the excitation from the collision between neutral atoms and electrons during the lifetime of the underdense plasma. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement