本文關(guān)鍵詞： 光擊穿 橢球模型 自由電子密度 閾值　出處：《激光雜志》2017年08期 　論文類型：期刊論文

【摘要】：基于橢球模型,考慮到脈沖激光的能量傳播特性,提出了聚焦區(qū)域的光強(qiáng)的表達(dá)式,分析了液體中光擊穿的機(jī)制,對于多光子電離誘導(dǎo)的雪崩電離,簡化了等離子體中自由電子密度演化過程的速率方程,修正了電子擴(kuò)散速率和雪崩電離速率,得到了雪崩電離產(chǎn)生的自由電子密度的解析表達(dá)式,并利用雪崩電離產(chǎn)生的自由電子密度的解析表達(dá)式,得到了長、短脈寬的雪崩電離擊穿光強(qiáng)閾值的解析表達(dá)式,進(jìn)而討論了長、短脈寬激光情況下,脈沖寬度、初始電子密度、擴(kuò)散速率以及復(fù)合速率對擊穿閾值的影響。此外,通過該解析表達(dá)式得到的光強(qiáng)閾值與實(shí)驗(yàn)結(jié)果符合較好。
[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.
【作者單位】： 河北師范大學(xué)匯華學(xué)院;陜西師范大學(xué)應(yīng)用聲學(xué)研究所;
【基金】：國家自然科學(xué)基金資助項(xiàng)目(11074159、11374199)
【分類號】：TN24
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本文編號：1545653