Abstract The electric field distribution of Ag nanoparticles under femtosecond laser is simulated by solving Maxwell equations in this article. The results show that with the same laser energy, the coupling electric field between adjacent nanoparticles becomes stronger and stronger as the spacing between nanoparticles decreases, while the enhancement factor decreases rapidly when the spacing between nanoparticles is less than 1 nm, because under this condition, its mechanism includes not only the coupling of two dipoles, but also the electron tunneling between two surfaces. Besides laser energy, the electric field of Ag nanoparticles is greatly affected by the nanoparticles size and their spatial distribution. With the same laser energy and spacing, the smaller the particle size, the higher the peak value of electric field intensity, but the faster the attenuation with distance. In the polarization direction of the laser, the enhancement factor of the electric field is more obvious. When the laser acts on several Ag nanoparticles, the electric field of nanoparticles in the range of spot size is quite different from that of the nanoparticles outside the spot.

中文翻译：

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飞秒激光在焊接过程中诱导纳米银的电场模拟

摘要 本文通过求解麦克斯韦方程组模拟了飞秒激光下银纳米粒子的电场分布。结果表明，在相同的激光能量下，随着纳米颗粒间距的减小，相邻纳米颗粒之间的耦合电场越来越强，而当纳米颗粒间距小于1 nm时，增强因子迅速减小，因为在这种条件下，其机理不仅包括两个偶极子的耦合，还包括两个表面之间的电子隧穿。除了激光能量，Ag 纳米粒子的电场受纳米粒子尺寸及其空间分布的影响很大。在相同的激光能量和间距下，粒径越小，电场强度峰值越高，但随着距离衰减越快。在激光器的偏振方向，电场的增强因子更为明显。当激光作用在几个Ag纳米粒子上时，光斑尺寸范围内的纳米粒子的电场与光斑外的纳米粒子的电场有很大不同。