Spatiotemporal Rogue Events in Optical Multiple Filamentation
Spatiotemporal Rogue Events in Optical Multiple Filamentation
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DOI：
10.1103/physrevlett.111.243903
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发表时间：
2013-12-10
影响因子：
8.6
通讯作者：
Steinmeyer, Gunter
中科院分区：
文献类型：
--
作者：
Birkholz, Simon;Nibbering, Erik T. J.;Steinmeyer, Gunter
通过实验研究了在氙气中形成的光纤灯丝的光束轮廓中短暂出现的亮点。使用高速光学相机以激光源的千赫兹重复率记录注量分布。统计分析揭示了重尾注量分布的阈值外观以及从单丝到多丝的转变。复丝情景表现出接近指数的概率密度函数，极端事件超过有效波高 10 倍以上。极端事件在空间和时间上都是孤立的。这些实验观察到的重尾统计数据的宏观起源被证明是由多光子吸收和随后的等离子体热化引起的非线性介质内的局部折射率变化。从微观上看，细丝串之间的合并似乎在观察到的异常波统计中起着决定性作用。
The transient appearance of bright spots in the beam profile of optical filaments formed in xenon is experimentally investigated. Fluence profiles are recorded with high-speed optical cameras at the kilohertz repetition rate of the laser source. A statistical analysis reveals a thresholdlike appearance of heavy-tailed fluence distributions together with the transition from single to multiple filamentation. The multifilament scenario exhibits near-exponential probability density functions, with extreme events exceeding the significant wave height by more than a factor of 10. The extreme events are isolated in space and in time. The macroscopic origin of these experimentally observed heavy-tail statistics is shown to be local refractive index variations inside the nonlinear medium, induced by multiphoton absorption and subsequent plasma thermalization. Microscopically, mergers between filament strings appear to play a decisive role in the observed rogue wave statistics.