Femtosecond filamentation by intensity clamping at a Freeman resonance
Femtosecond filamentation by intensity clamping at a Freeman resonance
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DOI：
10.1103/physreva.92.013813
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发表时间：
2014-12
期刊：
影响因子：
--
通讯作者：
M. Hofmann;C. Br'ee
中科院分区：
文献类型：
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作者：
M. Hofmann;C. Br'ee
我们证明了弗里曼共振对飞秒灯丝的非线性光学响应有很大的影响。这些共振降低了在一个狭窄的强度窗口内的瞬态折射率，并强烈地影响了折射动力学。特别是，我们证明了灯丝的峰值强度可以被钳位在这些共振，暗示存在新的制度的电子密度大大低于标准模型预测的双折射。这为有争议的高阶克尔模型所预言的非等离子体强度钳位和无等离子体细丝现象提供了新的解释。
We demonstrate that Freeman resonances have a strong impact on the nonlinear optical response in femtosecond filaments. These resonances decrease the transient refractive index within a narrow intensity window and strongly affect the filamentation dynamics. In particular, we demonstrate that the peak intensity of the filament can be clamped at these resonances, hinting at the existence of new regimes of filamentation with electron densities considerably lower than predicted by the standard model. This sheds a new light on the phenomenon of filamentary intensity clamping and the plasmaless filaments predicted by the controversial higher-order Kerr model.