AI 中文总结
本研究通过时间分辨横向光学衍射法揭示激光诱导等离子体电离后200皮秒内的空间演化特征，明确其非自相似演化源于电子-离子复合的局部密度依赖性，重构的局部复合定律可定量预测等离子体后续演化，相关结果对多个光学领域有重要意义。
AI 中文摘要
激光诱导等离子体的主要特征是其密度随时间衰减。利用时间分辨横向光学衍射法，我们揭示了它们同时发生的空间演化，发现在电离后的最初200皮秒内，等离子体出现明显的展宽和平坦化。这种非自相似演化源于电子-离子复合的局部密度依赖性，无粒子输运参与。借助单个等离子体盘内的初始密度连续体，我们在宽密度范围内实验重构了有效、随时间变化的局部复合定律。将该动力学映射局部应用于独立测量的初始等离子体轮廓，可定量预测其后续演化。这些结果与瞬态衍射光学、等离子体基光学元件及波导，以及将激光诱导等离子体作为气相太赫兹等离子激元平台的开发密切相关。
英文摘要
Laser-induced plasmas are primarily characterized by their temporal density decay. Using time-resolved transverse optical diffractometry, we reveal their concurrent spatial evolution, demonstrating pronounced broadening and flattening during the first 200 ps following ionization. This non-self-similar evolution arises from the local density dependence of electron-ion recombination, without particle transport. Exploiting the continuum of initial densities within a single plasma disc, we experimentally reconstruct an effective, time-dependent local recombination law over a broad density range. Applied locally to independently measured initial plasma profiles, this kinetic map quantitatively predicts their subsequent evolution. These results are relevant to transient diffractive optics, plasma-based optical elements and waveguides, and the development of laser-induced plasmas as platforms for gas-phase THz plasmonics.
Comments8 pages, 5 Figures
