Pulsed laser-assisted surface structuring with optical near-field enhanced effects
Pulsed laser-assisted surface structuring with optical near-field enhanced effects
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DOI：
10.1063/1.1501768
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发表时间：
2002-09-01
影响因子：
3.2
通讯作者：
Chong, TC
中科院分区：
文献类型：
--
作者：
Huang, SM;Hong, MH;Chong, TC
光学共振和近场对基底上透明颗粒与激光相互作用的影响已经通过实验和理论进行了检验。研究发现，单脉冲激光照射（KrF，lambda=248 nm）可以在颗粒与金属表面之间的接触点处产生凹坑。研究了颗粒尺寸和激光注量对表面结构的影响。颗粒的尺寸范围为直径1.0μm至140nm。所产生的孔的形态已通过原子力显微镜和扫描电子显微镜进行了表征。对于恒定的激光能量密度，所产生的孔对颗粒尺寸敏感。对于更高的激光能量密度，相应的孔变得更大更深。在 300 mJ/cm2 的低注量和 140 nm 颗粒的情况下，所创建的凹坑的横向尺寸可低至 30 nm。在 750 mJ/cm2 的高能量密度和 1.0 μm 颗粒的情况下，所产生的孔的直径和深度分别约为 350 和 100 nm。理论计算和边界问题的精确解决表明，入射光可以激发颗粒内部的某些共振模式，并在接触区域（基材表面）产生增强的光强度。接触区域的光强度不均匀并且对颗粒尺寸参数敏感。实验结果得到了解释，并且与理论计算结果非常一致。实验结果还提供了基板上透明颗粒与激光相互作用中光学共振和近场效应的直接证据。 (C) 2002 年美国物理研究所。
The effects of optical resonance and near field in the interaction of transparent particles on a substrate with laser light have been examined experimentally and theoretically. It is found that pits can be created at the contacting point between the particle and the metallic surface by laser irradiation (KrF,lambda=248 nm) with a single pulse. The influence of the particle size and the laser fluence on the structuring of the surface has been investigated. The size of the particle ranges from 1.0 mum to 140 nm in diameter. The morphologies of the holes created have been characterized by an atomic force microscope and a scanning electron microscope. For constant laser fluence, the created hole is sensitive to the particle size. For higher-laser fluence, the corresponding hole becomes larger and deeper. With a low fluence of 300 mJ/cm2 and for 140 nm particles, the lateral dimensions of created pits can be down to 30 nm. With a high fluence of 750 mJ/cm2 and 1.0 mum particles, the diameter and the depth of created holes are about 350 and 100 nm, respectively. Theoretical calculations and an accurate solution of a boundary problem indicate that incident light could excite some resonance modes inside the particle and produce enhanced light intensities on the contacting area (substrate surface). The light intensity on the contacting area is nonuniform and sensitive to the particle size parameter. Experimental results are explained and are very consistent with those of theoretical calculations. The experimental results also provide direct evidence of the optical resonance and near-field effects in the interaction of transparent particles on the substrate with laser light. (C) 2002 American Institute of Physics.