Spontaneous scaling down of femtosecond laser-induced apertures towards the 10-nanometer level: the excitation of quasistatic surface plasmons
Spontaneous scaling down of femtosecond laser-induced apertures towards the 10-nanometer level: the excitation of quasistatic surface plasmons
复制标题
飞秒激光诱导孔径自发缩小至 10 纳米水平：准静态表面等离子体激元的激发
DOI：
10.1002/lpor.201300212
复制
发表时间：
2014-07-01
影响因子：
11
通讯作者：
Xu, Zhizhan
中科院分区：
文献类型：
--
作者：
Huang, Min;Xu, Zhizhan
在超快激光烧蚀ZnO过程中，激光诱导孔洞的特征尺寸总是随着脉冲的增大和凹坑的扩展而自发减小，最终可能接近10 nm的尺度，这是一种超深亚波长激光与固体相互作用机制，涉及激光诱导损伤的新物理。基于等离子体激元的基本理论，提出了等离子体激元的自发缩比起源于等离子体激元相互作用的物理机制从光学机制向静电机制的转变，从而产生了远超过衍射极限的准静态等离子体激元，并导致了超快的非热烧蚀，从而产生了非常强的静电场。基本上，“纳米尺度”极大地消除了电磁阻滞效应，对入射场产生瞬时响应，并引起静电相互作用，产生巨大的局域场增强，对表面电子和离子产生巨大的静电力，最终导致“超快”静电纳米爆炸。因此，在飞秒激光烧蚀中，同时出现了“纳米级”和“超快”的特性。
During ultrafast laser ablation on ZnO, the feature sizes of laser-induced apertures always decrease spontaneously with the pulse increasing and the crater extending, and may eventually approach an astonishing 10-nm scale, an ultradeep-subwavelength laser-solid interaction regime relating new physics in laser-induced damage. Based on the fundamental theories of plasmonics, it is proposed that the spontaneous scaling-down originates in the conversion of physical regimes of plasmonic interaction from the optical regime to the electrostatic regime, which arouses quasistatic SPs with interaction scales far beyond the diffraction limit and results in ultrafast, nonthermal ablation for extraordinary electrostatic field enhancement. Basically, "nanoscale" eliminates electromagnetic retardation effects greatly, brings an instantaneous respond to the incident field, and arouses electrostatic interactions with giant local-field enhancement, which may exert tremendous electrostatic forces on superficial electrons and ions and eventually lead to an "ultrafast" electrostatic nanoexplosion. Thus, the characteristics of simultaneous "nanoscale" and "ultrafast" arise spontaneously in femtosecond laser ablation.