Enhanced focusing of relativistic lasers by plasma lens with exponentially increasing density profiles
Enhanced focusing of relativistic lasers by plasma lens with exponentially increasing density profiles
复制标题
通过等离子体透镜增强相对论激光的聚焦，密度分布呈指数增加
DOI：
10.1063/1.4985087
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发表时间：
2017
影响因子：
2.2
通讯作者：
Zhao Zongqing
中科院分区：
文献类型：
--
作者：
Yang Yue;Zhang Zhimeng;Jiao Jinlong;Tian Chao;Cao Lihua;Wu Yuchi;Dong Kegong;Zhou Weimin;Gu Yuqiu;Zhao Zongqing
研究了密度分布呈指数增长的等离子体透镜中超强激光的自聚焦现象。通过理论估计和三维粒子模拟验证了该设计的鲁棒性。与优化的均匀等离子体透镜相比，调制指数密度等离子体透镜对自聚焦过程中激光强度的增加进行了密度补偿，可以有效地将激光聚焦到更高的峰值强度和更小的光斑。在近临界密度等离子体中，激光聚焦经历了两个阶段，其主要机制不同：早期的自聚焦和等离子体通道中的磁约束。指数密度等离子体在这两个阶段都有更好的增强效果。通过理论推导，估计了这种等离子体透镜的焦点位置和最佳密度尺度长度。我们的研究结果表明，预等离子体的可能性，实验作为一种新的等离子体透镜，以获得相对论性的激光。
The self-focusing of ultraintense laser in plasma lenses with exponentially increasing density profiles is studied. And the robustness of this design is proved by theoretical estimates and 3D particle-in-cell simulations. Attributed to the density compensation for the increase of laser intensity during self-focusing, a modulated exponential density plasma lens can efficiently focus the laser to higher peak intensity and smaller spot than that by using optimized uniform plasma lens. In near critical density plasmas, laser focusing experiences two stages with different dominant mechanisms: self-focusing at earlier time and magnetic constraint in the plasma channel. And more enhanced effects are achieved by exponential density plasma in both stages. The focal position and the optimal density scalelength for this kind of plasma lens are also estimated through theoretical derivation. Our findings indicate the possibility for the preplasma to experimentally serve as a novel plasma lens to obtain relativistic la...