空气呼吸模式CO_2激光等离子体光谱观察  

Observation of breakdown induced by CO_2 laser with air-breathing mode

作　　者：余亮英[1] 程祖海[1] 左都罗[1] 陈钰琦[1] 曹华梁[1] 

机构地区：[1]武汉光电国家实验室

出　　处：《应用光学》2007年第6期751-755,共5页Journal of Applied Optics

基　　金：国家安全重大基础研究973项目(61328)

摘　　要：为了了解采用脉冲CO2激光推进空气呼吸模式时光船参数等对产生等离子体的影响,介绍了利用实验室自行研制的紫外预电离TEA CO2激光器进行的激光等离子体实验。实验采用底面直径为60 mm、焦距为5 mm和10 mm的抛物面光船。介绍了空气呼吸模式激光等离子体的谱和明显的特征谱线,以及等离子体的时间演化过程。结果表明:空气呼吸模式等离子体的持续时间约为20μs,在6μs左右时信号强度达到最大值;激光脉冲作用后,信号迅速衰减;10 mm光船产生的等离子体信号峰值和持续时间均略长于5 mm光船的。In order to study the influence of flight parameters on laser-induced plasma when the pulse CO2 laser is used for the air-breathing mode, the experiment of laser-induced plasma using the UV-preionized TEA CO2 laser made in our laboratory is discussed. A cylinder with a parabolic inner surface was used in this experiment, whose aperture diameter was 60 mm, and the focal lengths were 5 mm and 10 mm. The spectrum of laser-induced plasma, the distribution of characteristic lines, and the temporal behaviors of plasma in air-breathing mode were introduced in detail. The results show that the evolution of laser-induced plasma with airbreathing mode may last 20 μs, and the signal intensity reaches maximum at 6 μs. When the laser pulse has a complete effect, the signal begins to decay rapidly. In addition, the signal peak value and the persistence time of laser plasma produced by 10 mm parabolic inner surface are higher and longer than those by the short focal length flight.

关 键 词：激光等离子体 光谱测量术 CO2 激光器 空气呼吸模式 

分 类 号：TN248[电子电信—物理电子学] O433[机械工程—光学工程]