液体中光击穿阈值的解析研究
发布时间:2018-02-28 03:54
本文关键词: 光击穿 椭球模型 自由电子密度 阈值 出处:《激光杂志》2017年08期 论文类型:期刊论文
【摘要】:基于椭球模型,考虑到脉冲激光的能量传播特性,提出了聚焦区域的光强的表达式,分析了液体中光击穿的机制,对于多光子电离诱导的雪崩电离,简化了等离子体中自由电子密度演化过程的速率方程,修正了电子扩散速率和雪崩电离速率,得到了雪崩电离产生的自由电子密度的解析表达式,并利用雪崩电离产生的自由电子密度的解析表达式,得到了长、短脉宽的雪崩电离击穿光强阈值的解析表达式,进而讨论了长、短脉宽激光情况下,脉冲宽度、初始电子密度、扩散速率以及复合速率对击穿阈值的影响。此外,通过该解析表达式得到的光强阈值与实验结果符合较好。
[Abstract]:Based on the ellipsoid model and considering the energy propagation characteristics of pulsed laser, the expression of light intensity in the focus region is proposed, and the mechanism of optical breakdown in liquid is analyzed, and the avalanche ionization induced by multiphoton ionization is analyzed. The rate equation of free electron density evolution in plasma is simplified, the electron diffusion rate and avalanche ionization rate are modified, and the analytical expression of free electron density produced by avalanche ionization is obtained. Using the analytical expression of the free electron density produced by avalanche ionization, the analytical expressions of the light intensity threshold of avalanche ionization with long and short pulse width are obtained, and the pulse width and initial electron density are discussed in the case of long and short pulse width laser. The influence of diffusion rate and recombination rate on the breakdown threshold is also discussed. In addition, the light intensity threshold obtained by the analytical expression is in good agreement with the experimental results.
【作者单位】: 河北师范大学汇华学院;陕西师范大学应用声学研究所;
【基金】:国家自然科学基金资助项目(11074159、11374199)
【分类号】:TN24
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本文编号:1545653
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