Plasma induced laser beam smoothing below the filamentation threshold
Plasma induced laser beam smoothing below the filamentation threshold
复制标题
等离子体诱导激光束平滑至丝化阈值以下
DOI：
10.1063/1.2337791
复制
发表时间：
2006
影响因子：
2.2
通讯作者：
S. Weber
中科院分区：
文献类型：
--
作者：
M. Grech;V. Tikhonchuk;G. Riazuelo;S. Weber
本文用统计方法描述了激光场与低密度等离子体的相互作用，并讨论了在低于等离子体传输阈值的功率下，激光束在等离子体中传输时的时间相干性。从随机波动方程出发，导出了随机激光束驱动等离子体密度扰动的主要性质。的激光光谱和角展宽示出发生的距离，基本上取决于在一个散斑的临界功率的平均功率的比率。透射光的相干时间减少到等离子体对激光的声学响应时间。它通常是几皮秒。为了分析激光和等离子体的统计特性，已经为相互作用代码PARAX开发了专用的诊断程序。发现等离子体长度对透射光相干性的影响与理论预测吻合得很好。前向受激布里渊...
This paper deals with a statistical approach for description of the laser field interaction with underdense plasmas and modification of the laser beam temporal coherence during its propagation through a plasma at power well below the filamentation threshold. The main properties of the plasma density perturbations driven by a randomized laser beam are derived from a stochastic wave equation. The laser spectral and angular broadening is shown to occur on a distance that depends essentially on the ratio of the average power in a speckle to the critical power for filamentation. The coherence time of the transmitted light is reduced to the plasma acoustic time of response to the laser. It is typically a few picoseconds. Dedicated diagnostics have been developed for the interaction code PARAX in order to analyze the laser and plasma statistical properties. The effect of the plasma length on the transmitted light coherence is found to be in good agreement with theoretical predictions. Forward stimulated Brilloui...