Lin L, Huang H, Sivayoganathan M, Liu L, Zou G, Duley W W, Zhou Y
Appl Opt. 2015 Mar 20;54(9):2524-31. doi: 10.1364/AO.54.002524.
In this work, we show that well-ordered structures of silver nanoparticles on nanowire substrates can be produced by irradiation with femtosecond (fs) laser pulses at fluences ranging from 10.3 to 15.9 mJ/cm if the direction of polarization is parallel to the long axis of the nanowire. Experimental results show that a uniformly spaced distribution of nanoparticles is more readily produced on nanowires with lengths L≤2λ, where λ=800 nm is the laser wavelength. The distribution of nanoparticles is found to become less well organized as L≥2λ. Finite element method simulations, combined with experimental observations, indicate that nanoparticles are initially distributed in response to the electric field along the clean Ag nanowire arising from optical excitation. This electric field is responsible for the attraction of nanoparticles to certain locations on the nanowire. We show how a fs-laser-driven assembly of nanoparticles on nanowires can be used in the development of a nanoscale optical logic processor. This method of creating periodic arrays of metallic nanoparticles on nanowire substrates then has many possible applications in electro-optics.
在这项工作中，我们表明，如果偏振方向平行于纳米线的长轴，通过用飞秒（fs）激光脉冲以10.3至15.9 mJ/cm的能量密度进行辐照，可以在纳米线基底上制备出排列有序的银纳米颗粒结构。实验结果表明，在长度L≤2λ（其中λ = 800 nm为激光波长）的纳米线上更容易产生均匀间隔分布的纳米颗粒。当L≥2λ时，发现纳米颗粒的分布变得不那么规则。有限元方法模拟与实验观察相结合表明，纳米颗粒最初是响应于由光激发在清洁的银纳米线上产生的沿其方向的电场而分布的。该电场导致纳米颗粒被吸引到纳米线上的特定位置。我们展示了如何将飞秒激光驱动的纳米颗粒在纳米线上的组装用于纳米级光学逻辑处理器的开发。然后，这种在纳米线基底上创建金属纳米颗粒周期性阵列的方法在电光领域有许多可能的应用。
