Self-waveguiding of relativistic laser pulses in neutral gas channels
Self-waveguiding of relativistic laser pulses in neutral gas channels
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DOI：
10.1103/physrevresearch.2.043173
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
L. Feder;B. Miao;J. Shrock;A. Goffin;H. Milchberg
中科院分区：
文献类型：
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作者：
L. Feder;B. Miao;J. Shrock;A. Goffin;H. Milchberg
我们证明了一个超短高强度激光脉冲可以在准备好的中性氢通道中传播数百个瑞利范围，它在传播时产生自己的等离子体波导；脉冲的前端产生一个限制脉冲其余部分的波导。一系列合适的初始折射率结构将支持这种“自波导”过程；必要的特征是气体在轴上的密度最小。在这里，我们演示了至少$1.5\x 10^{17}W/cm^2$(归一化矢量势$a_0\sim0.3)$在10厘米或$\sim100$瑞利范围内的自波导，仅受激光能量和气体射流长度的限制。我们预测并观察到了自波导中与模式跳动相对应的特征振荡。自波导脉冲在尾流中留下一个完全电离的低密度等离子体波导，它可以引导紧随其后注入的另一个脉冲；我们演示了这种后续探测脉冲的光学引导
We demonstrate that an ultrashort high intensity laser pulse can propagate for hundreds of Rayleigh ranges in a prepared neutral hydrogen channel by generating its own plasma waveguide as it propagates; the front of the pulse generates a waveguide that confines the rest of the pulse. A wide range of suitable initial index structures will support this "self-waveguiding" process; the necessary feature is that the gas density on axis is a minimum. Here, we demonstrate self-waveguiding of pulses of at least $1.5\times10^{17} W/cm^2$ (normalized vector potential $a_0\sim0.3)$ over 10 cm, or $\sim100$ Rayleigh ranges, limited only by our laser energy and length of our gas jet. We predict and observe characteristic oscillations corresponding to mode-beating during self-waveguiding. The self-waveguiding pulse leaves in its wake a fully ionized low density plasma waveguide which can guide another pulse injected immediately following; we demonstrate optical guiding of such a follow-on probe pulse