The guiding of a 6 GHz electromagnetic (EM) wave along a plasma filament produced by intense femtosecond laser pulses is investigated with the electromagnetic simulation software XFDTD. The results confirm that the plasma filament can guide the EM wave over a long distance, with low attenuation relative to freely propagating the signal. Furthermore, the filament can change the phase wavelength of the signal in the waveguide. Also notable is that the power density of the wave along the filament monotonically decreases with increasing EM wave propagation length. The wavelength of the EM wave along the plasma filament is about 4.98 cm, which is slightly less than that of the incident 6 GHz signal, i.e., the wave velocity along the filament is less than the speed of light.

中文翻译：

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单束激光等离子体灯丝对6 GHz电磁波的引导性能

使用电磁仿真软件XFDTD研究了6 GHz电磁（EM）波沿由强飞秒激光脉冲产生的等离子体灯丝的导引。结果证实，等离子灯丝可以在很长的距离上引导EM波，相对于自由传播的信号，衰减很小。此外，灯丝可以改变波导中信号的相位波长。同样值得注意的是，沿着灯丝的波功率密度随EM波传播长度的增加而单调降低。沿等离子体灯丝的EM波的波长约为4.98厘米，略小于入射的6 GHz信号的波长，即沿灯丝的波速小于光速。