Malkin VM, Shvets G, Fisch NJ
Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA.
Phys Rev Lett. 2000 Feb 7;84(6):1208-11. doi: 10.1103/PhysRevLett.84.1208.
The recently proposed scheme of so-called "fast compression" of laser pulses in plasma can increase peak laser intensities by 10(5) [Phys. Rev. Lett. 82, 4448 (1999)]. The compression mechanism is the transient stimulated Raman backscattering, which outruns the fastest filamentation instabilities of the pumped pulse even at highly overcritical powers. This Letter proposes a novel nonlinear filtering effect that suppresses premature backscattering of the pump in a noisy plasma layer, while the desired amplification of a sufficiently intense seed persists with a high efficiency. The effect is of basic interest and also makes it robust to noise the simplest technologically fast compression scheme.
最近提出的在等离子体中对激光脉冲进行所谓“快速压缩”的方案，可以将激光峰值强度提高10⁵[《物理评论快报》82, 4448 (1999)]。压缩机制是瞬态受激拉曼背向散射，即使在高过临界功率下，它也能超过泵浦脉冲最快的丝状不稳定性。本文提出了一种新颖的非线性滤波效应，可抑制泵浦在有噪声的等离子体层中的过早背向散射，而足够强的种子光的所需放大则能高效持续。该效应具有基本的研究意义，并且使最简单的技术上可行的快速压缩方案对噪声具有鲁棒性。
