Fine 3D control of THz emission in air with dual femtosecond laser pre-pulses at tunnelling ionisation regime  

作　　者：Hsin-Hui Huang Takeshi Nagashima Kota Kumagai Yoshio Hayasaki Saulius Juodkazis Vladimir T.Tikhonchuk Koji Hatanaka 

机构地区：[1]Optical Sciences Centre,ARC Training Centre in Surface Engineering for Advanced Materials(SEAM),School of Science,Swinburne University of Technology,Hawthorn,Victoria 3122,Australia [2]Faculty of Science and Engineering,Setsunan University,17-8 Ikeda-Nakamachi,Neyagawa,Osaka,572-8508,Japan [3]Center for Optical Research and Education(CORE),Utsunomiya University,7-1-2 Yoto,Utsunomiya 321-8585,Japan [4]WRH Program International Research Frontiers Initiative(IRFI)Tokyo Institute of Technology,Nagatsuta-cho,Midori-ku,Yokohama,Kanagawa 226-8503 Japan [5]Laser Research Center,Physics Faculty,Vilnius University,Sauletekio Ave.10,10223 Vilnius,Lithuania [6]Centre Lasers Intenses et Applications,Universite de Bordeaux,351,Cours de la Liberation,33405 Talence cedex,France [7]Extreme Light Infrastructure ERIC,ELI Beamlines Facility,Za Radnicic 835,25241 Dolni Břežany,Czech Republic [8]Organization for Research Strategy and Development,Okayama Univ.1-1-1 Tsushima-naka,Kita-ku,Okayama 700-8530,Japan

出　　处：《Light(Advanced Manufacturing)》2024年第3期62-74,共13页光（先进制造）（英文）

基　　金：funded by programs 107-2112-M-001-014-MY3,110-2112-M-001-054(K.H.and H-H.H.);partly funded by the Australian Research Council Linkage LP 220100153 grant(S.J.).We are grateful to Prof.Eugene G.Gamaly for the critical comments.

摘　　要：Emission of THz radiation from air breakdown at focused ultra-short fs-laser pulses(800 nm/35 fs)was investigated for the 3D spatio-temporal control where two pre-pulses are used before the main-pulse.The laser pulse induced air breakdown forms a~120μm-long focal volume generate shockwaves which deliver a denser air into the focal region of the main pulse for enhanced generation of THz radiation at 0.1-2.5 THz spectral window.The intensity of 162 pre-and main-pulses was at the tunnelling ionisation intensities(1-3)×10 W/cm and corresponded to sub-critical(transparent)plasma formation in air.Polarisation analysis of THz radiation revealed that orientation of the air density gradients generated by pre-pulses and their time-position locations defined the ellipticity of the generated THz electrical field.The rotational component of electric current is the origin of THz radiation.

关 键 词：THz radiation Femtosecond laser induced breakdown Air breakdown spatio-temporal control 

分 类 号：TN249[电子电信—物理电子学]