通过数值模拟光丝与负电晕相互作用过程中的空间电场分布,实验观测飞秒激光诱导负电晕放电现象, 研究了空气中飞秒激光光丝与针-板电极结构中产生的负电晕之间的相互作用的规律和机理。模拟和实验结果表明,在相互作用过程中, 光丝末端出现高于雪崩电离阈值的空间电场分布, 产生了负电晕放电现象。通过调控光丝长度可以控制负电晕的作用区域, 由此提出一种全光诱导负电晕的新方法。

The investigation on the interaction between femtosecond laser filaments in air and negative corona discharge in the needle-plane electrode is reported. The spatial distribution of electric field of the interaction is theoretically simulated and the phenomena of laser guided negative corona is observed experimentally during the interaction process. The setup is established to understand this process. Both the simulation and experiment results show that the electric field distributions with the strength higher than the threshold for avalanche ionization do exist during the interaction process. As a consequence negative corona is guided at the end of laser filament. The negative corona area can be altered through the control of filament length, which provides a new method to optically guide negative corona.