In this work a method based on self-mixing interferometry (SMI) is presented for probing the concentration of plasma plumes induced by multi-pulse laser ablation. An analytical model is developed to interpret the single-arm interferometric signal in terms of plasma electron number density. Its time dependence follows a power-law scaling which is determined by concurrent effects of plume accumulation and propagation. The model has been applied for the experimental study of plume formation at variable laser pulse frequencies on different materials. The plume expansion dynamics has been observed with high-speed imaging, and the SMI measurements allowed for a time-resolved estimation of the electron number density. The intrinsic advantages of the SMI technique in terms of robustness and low intrusiveness would allow for its usage as a fast diagnostic tool for the dynamical scaling of laser-induced plumes. Moreover it can be easily applied in laser-based manufacturing technologies wh...

中文翻译：

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使用自混合干涉术对多脉冲激光烧蚀引起的血浆累积进行时间分辨量化

在这项工作中，提出了一种基于自混合干涉术（SMI）的方法，用于探测由多脉冲激光烧蚀引起的等离子体羽流的浓度。开发了一种分析模型，以根据等离子体电子数密度来解释单臂干涉测量信号。它的时间依赖性遵循幂律定标，幂定标定标由羽流累积和传播的并行效应确定。该模型已用于不同材料的可变激光脉冲频率下羽流形成的实验研究。高速成像已观察到羽流膨胀动力学，并且SMI测量可实现时间分辨的电子数密度估计。SMI技术在鲁棒性和低侵入性方面的内在优势将使其可以用作动态诊断激光诱导羽流的快速诊断工具。此外，它可以很容易地应用于基于激光的制造技术中。