Cheng Huachao, Li Peng, Liu Sheng, Lu Hua, Han Lei, Zhao Jianlin
Appl Opt. 2020 Aug 20;59(24):7211-7216. doi: 10.1364/AO.397888.
The polarization ripples on many materials have been intensively studied and have yielded significant applications such as modulating light fields, building hydrophobic or hydrophilic surfaces, and fabricating tunable thermal sources. It was shown that ripples are closely dependent on the ablation threshold of laser fluence and orientation of laser polarization. Here we demonstrate that laser polarization ellipticity also represents the switching effect on the formation of ripples. Two significantly different damage morphologies, ripples and hollows, are respectively observed below and above the switching value of incident laser polarization ellipticity. Furthermore, it is demonstrated that this ellipticity switching value varies with laser pulse energy and pulse number. These intriguing phenomena are qualitatively explained using a laser-surface plasmon polariton interference mechanism. Finally, we achieve the analogous laser-assisted nanopatterning by using a femtosecond laser beam with spatially inhomogeneous polarization state, demonstrating the application potential of these switchable nanoripples in laser-assisted nanopatterning.
许多材料上的极化波纹已得到深入研究，并产生了诸如调制光场、构建疏水或亲水表面以及制造可调热源等重要应用。研究表明，波纹与激光能量密度的烧蚀阈值以及激光偏振方向密切相关。在此，我们证明激光偏振椭圆率对波纹的形成也具有开关效应。在入射激光偏振椭圆率的开关值以下和以上分别观察到两种显著不同的损伤形态，即波纹和空洞。此外，还证明了该椭圆率开关值随激光脉冲能量和脉冲数而变化。利用激光 - 表面等离子体激元干涉机制对这些有趣的现象进行了定性解释。最后，我们通过使用具有空间不均匀偏振态的飞秒激光束实现了类似的激光辅助纳米图案化，证明了这些可切换纳米波纹在激光辅助纳米图案化中的应用潜力。
