Long plasma channels in air induced by femtosecond laser pulses are inves-tigated using three different methods, including the cross-section imaging, resistivity measuring and acoustic diagnostics. These methods are based on different properties of the light filaments. A comparison of the three diagnostics shows that the imaging method is the most precise one in studying the filaments distribution and evolution, that the sono-graphic method is the most convenient approach to detecting long plasma channels by detecting the acoustic wave generation, and that the resistivity measurement can only be applied for giving a rough estimate. The diagnostics of filaments allow us to choose ap-propriate detecting methods and provide further insight into the dynamic evolution of the light filaments in air.
HAO Zuoqiang1, ZHANG Jie1, YU Jin2, ZHENG Zhiyuan1, YUAN Xiaohui1,3, ZHANG Zhe1, LI Yutong1, WANG Zhaohua1, LING Weijun1 & WEI Zhiyi11. Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
The characteristics of hot electrons produced by p-polarized femtosecond laser-solid interactions are studied. The experimental results show that the outgoing electrons are mainly emitted in three directions: along the target surface, the normal direction and the laser backward direction. The electrons flowing along the target surface are due to the confinement of the electrostatic field and the surface magnetic field, while the electrons in the normal direction due to the resonant absorption.
XU Miaohua1, LI Yutong1, YUAN Xiaohui1,2, ZHENG Zhiyuan1, LIANG Wenxi1, YU Quanzhi1, ZHANG Yi1, WANG Zhaohua1, WEI Zhiyi1 & ZHANG Jie1 1. Key Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
