We propose a new laser amplifier scheme utilizing stimulated Raman scattering in plasma in conjunction with a “flying focus”—a chromatic focusing system combined with a chirped pump beam that provides spatiotemporal control over the pump’s focal spot. Pump intensity isosurfaces are made to propagate at $v=-c$ so as to be in sync with the injected counterpropagating seed pulse. By setting the pump intensity in the interaction region to be just above the ionization threshold of the background gas, an ionization wave is produced that travels at a fixed distance ahead of the seed. Simulations show that this will make it possible to optimize the plasma temperature and mitigate many of the issues that are known to have impacted previous Raman amplification experiments, in particular, the growth of precursors.

中文翻译：

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聚焦拉曼放大

我们提出了一种新的激光放大器方案，该方案利用等离子体中的受激拉曼散射与“飞行焦点”结合使用-一种彩色聚焦系统，结合a声泵浦光束，可对泵浦光斑进行时空控制。使泵浦强度等值面在$v=-C$以便与注入的反向传播种子脉冲同步。通过将相互作用区域中的泵浦强度设置为刚好高于背景气体的电离阈值，就产生了一个电离波，该电离波以一定距离传播到种子前面。仿真表明，这将使优化等离子体温度和减轻许多已知影响先前拉曼扩增实验的问题成为可能，特别是前体的生长。