Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2012 Jun 15;108(24):245004. doi: 10.1103/PhysRevLett.108.245004. Epub 2012 Jun 12.
Nonlinear electron trapping physics governs the onset and saturation of stimulated Raman scattering (SRS) in laser beams with many speckles. Hot electrons from intense speckles, produced during SRS daughter electron-plasma-wave bowing and filamentation, seed and enhance the growth of SRS in neighboring speckles by reducing Landau damping. Trapping-induced nonlinearity and speckle interaction through transport of hot electrons and back- and sidescattered SRS waves enable the system of speckles to self-organize and exhibit coherent, sub-ps SRS bursts with more than 100% instantaneous reflectivity, consistent with a SRS transverse coherence width much larger than a speckle width.
非线性电子俘获物理控制了具有多个斑点的激光束中受激喇曼散射(SRS)的起始和饱和。在 SRS 子电子等离子体波弯曲和细丝化过程中产生的强斑点中的热电子,通过减少 Landau 阻尼,在相邻斑点中产生并增强 SRS 的生长。通过热电子的输运和反向散射及侧向散射 SRS 波的斑点相互作用引起的俘获诱导非线性,使斑点系统能够自组织并表现出相干的、亚皮秒级 SRS 脉冲,其瞬时反射率超过 100%,这与 SRS 横向相干宽度远大于斑点宽度一致。