发表机构
Tata Institute of Fundamental Research（塔塔基础研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
飞秒激光诱导空化可在液射流上产生可控扰动，实现超越瑞利-普拉托稳定性极限（kR>1，最高1.9）的确定性破碎，并支持高达0.2 MHz的液滴生成。
AI 中文摘要
瑞利-普拉托不稳定性预测，液射流的无穷小扰动仅在kR < 1时增长，其中kR = 1标志着经典稳定性边界。在此，我们展示了飞秒激光诱导空化在流动液射流上产生局部的、脉冲式反冲扰动，从而实现了在(kR, ε/R)平面上射流破碎的二维映射。扰动的间距（波长）和强度（振幅）分别由激光重复频率和脉冲能量独立设定。在低振幅下，调节重复频率可恢复经典的瑞利-普拉托色散关系及其kR = 1的截止点，而增加波长则可实现单分散液滴串、双分散液滴群体以及最终孤立的单个液滴的可控生成。沿振幅轴，低脉冲能量产生的种子仅放大所施加的波数，而高于临界能量Ec时，种子展宽以同时激发多个波数。在更高振幅下，我们展示了kR > 1（延伸至kR = 1.9）的确定性破碎，激光同步液滴产生速率高达0.2 MHz。这些结果确立了局域飞秒激光诱导空化作为在经典线性稳定性边界之内和之外实现可控瑞利-普拉托破碎的途径。
英文摘要
The Rayleigh-Plateau instability predicts that infinitesimal perturbations of a liquid jet grow only for kR < 1, with kR = 1 marking the classical stability boundary. Here, we show that femtosecond-laser-induced cavitation generates a localized, impulsive recoil perturbation on a flowing liquid jet, enabling a two-dimensional map of jet breakup across the (kR, epsilon/R) plane. The perturbation's spacing (wavelength) and strength (amplitude) are set independently by the laser repetition rate and pulse energy, respectively. At low amplitudes, tuning the repetition rate recovers the classical Rayleigh-Plateau dispersion relation and its kR = 1 cutoff, while increasing the wavelength enables controlled generation of monodisperse droplet trains, bidisperse droplet populations, and ultimately isolated single droplets. Along the amplitude axis, low pulse energies produce a seed that amplifies only the imposed wavenumber, whereas above a critical energy Ec, the seed broadens to excite many wavenumbers simultaneously. At still higher amplitudes, we demonstrate deterministic breakup for kR > 1, extending to kR = 1.9, with laser-synchronized droplet production rates up to 0.2 MHz. These results establish localized femtosecond-laser-induced cavitation as a route to controlled Rayleigh-Plateau breakup both within and beyond the classical linear-stability boundary.
