Filamentation of femtosecond light pulses in the air: turbulent cells versus long-range clusters.
Filamentation of femtosecond light pulses in the air: turbulent cells versus long-range clusters.
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DOI：
10.1103/physreve.70.046602
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发表时间：
2004-10
期刊：
影响因子：
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通讯作者：
S. Skupin;L. Bergé;U. Peschel;Falk Lederer;G. Méjean;Jin Yu;Jérôme Kasparian;E. Salmon;
中科院分区：
文献类型：
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作者：
S. Skupin;L. Bergé;U. Peschel;Falk Lederer;G. Méjean;Jin Yu;Jérôme Kasparian;E. Salmon;
对超短脉冲在空气中的成丝现象进行了理论和实验研究。从理论的角度来看，光束的传播是由小尺度细胞的随机成核和长波导的弛豫相互作用驱动的。经过一个位置和振幅变化的瞬态阶段后，由各向同性噪声触发的细丝被限制在不同的簇中，称为“光柱”，其演变可以通过从超短脉冲的标准传播方程导出的平均时间二维（2D）模型来近似。该模型的计算结果与空间分辨和时间分辨的数值模拟结果进行了比较。从实验的角度来看，类似的细丝团簇出现在由Teramobile激光设备提供的初始光束轮廓的缺陷中。二维简化模型再现了细丝图案演变过程中的定性特征。
The filamentation of ultrashort pulses in air is investigated theoretically and experimentally. From the theoretical point of view, beam propagation is shown to be driven by the interplay between random nucleation of small-scale cells and relaxation to long waveguides. After a transient stage along which they vary in location and in amplitude, filaments triggered by an isotropic noise are confined into distinct clusters, called "optical pillars," whose evolution can be approximated by an averaged-in-time two-dimensional (2D) model derived from the standard propagation equations for ultrashort pulses. Results from this model are compared with space- and time-resolved numerical simulations. From the experimental point of view, similar clusters of filaments emerge from the defects of initial beam profiles delivered by the Teramobile laser facility. Qualitative features in the evolution of the filament patterns are reproduced by the 2D reduced model.