Femtosecond-laser nanofabrication onto silicon surface with near-field localization generated by plasmon polaritons in gold nanoparticles with oblique irradiation
Femtosecond-laser nanofabrication onto silicon surface with near-field localization generated by plasmon polaritons in gold nanoparticles with oblique irradiation
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DOI：
10.1007/s00339-009-5313-0
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发表时间：
2009-09-01
影响因子：
2.7
通讯作者：
Obara, M.
中科院分区：
文献类型：
--
作者：
Miyanishi, T.;Sakai, T.;Obara, M.
研究了不同入射角的飞秒激光辐照金纳米粒子制备纳米孔的过程。在本研究中使用的纳米粒子的直径为200 nm和中心波长为800 nm的激光照射。利用时域有限差分法（FDTD）对粒子近场区的电磁场分布进行了仿真分析。结果表明，金纳米粒子在激光脉冲辐照下可产生表面等离子体激元激发，并在粒子周围的有限区域内产生高强度的近场。研究发现，通过改变不同入射方向的辐照条件，可以实现具有可调特性的激光纳米加工。我们的研究结果表明，增强的光强度是能够诱导在基板表面上，无论入射方向的激光，由于图像电荷与基板的相互作用。此外，以一定角度使用p偏振激光照射给出了基底上的增强区的最小空间尺寸，其比在垂直入射下获得的空间尺寸小约两倍。
Nanohole fabrication process with gold nanoparticles irradiated by femtosecond laser at different incident angles is investigated. Nanoparticles with diameter of 200 nm and laser irradiation with center wavelength of 800 nm are used in the present study. The analysis of the electromagnetic field distribution in the near-field zone of the particle is made by simulations based on finite-differential time domain (FDTD) method. It is shown that when gold nanoparticle is irradiated by laser pulse surface plasmon excitation can be induced, and associated with it, high-intensity near field is produced in a limited area around the particle. It is found that the change of the irradiation conditions by means of irradiation from various incident directions gives a possibility of laser nanoprocessing with tunable characteristics. Our results show that enhanced optical intensity is able to be induced on the substrate surface regardless of incident direction of the laser due to the image charge interaction with the substrate. Furthermore, the use of p-polarized laser irradiation at a certain angle gives a minimum of the spatial dimensions of the enhanced zone on the substrate which is about two times smaller than that obtained at normal incidence.