面向在轨遥感应用的飞秒激光成丝调制延长方法研究

Femtosecond Laser Filamentation Modulation Extension for the Remote Sensing Application in Orbit

飞秒激光在大气中的远距离传输对于实时快速的遥感探测具有重要的应用价值。文章通过在聚焦镜前增加圆孔石英板,提出了一种延长激光光丝产生等离子体通道的新方法,结果显示飞秒激光等离子体通道延长了一倍;同时,研究了不同激光脉冲能量下,圆孔石英板的直径和厚度对形成的等离子体通道的影响,发现石英板中心圆孔的直径对形成光丝长度具有显著影响。基于延长的飞秒激光光丝,探测了氦气中充入空气量对混合气体光谱的影响,发现光谱信息对氦气的浓度变化非常敏感。

The long-distance propagation of femtosecond lasers in the atmosphere has important application value for real-time and rapid remote sensing detection.In this paper,a new method for extending the laser filament to generate plasma channels is proposed by adding round-hole quartz plates in front of the focusing mirror,and the results show that the length of femtosecond laser plasma channels are doubled.At the same time,the effect of the diameter and thickness of the round hole quartz plate on the formation of plasma channels under different laser pulse energies was studied,and it was found that the diameter of the round hole in the center of the quartz plate had a significant impact on the length of the formed filament.Based on the extended filament,the effect of the amount of air filled in helium on the spectrum of the gas mixture was studied.