Grześkiewicz Bartłomiej, Ptaszyński Krzysztof, Kotkowiak Michał
Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13a, 60-965 Poznań, Poland.
Plasmonics. 2014;9(3):607-614. doi: 10.1007/s11468-014-9671-x. Epub 2014 Mar 7.
Photonic devices can be developed, and their working principle can be understood only by considering the phenomena taking place at the nanoscale level. Optical properties of plasmonic structures depend on their geometric parameters and are sensitive to them. Recently, many advanced methods for the preparation of nanostructures have been proposed; however still, the geometric parameters are inaccurate. Numerical simulations provide a powerful tool for the analysis of plasmonic nanostructures. To the best of our knowledge, there are not many papers on near-field and far-field properties of single nanoprism and nanoprism dimer, the so-called bowtie, with rounded edges. For this purpose, Finite Integration Technique implemented to the CST Microwave Studio was used. Besides the edge rounding, an additional modification of the resonance modes was investigated, achieved by placement of a spherical nanoparticle in the gap between the prisms. Results of numerical simulations indicate that the radius of the curvature edges strongly affects the plasmon peak localization, and this effect cannot be neglected in plasmonic device design. Increase in the radius of edge curvature causes main extinction cross-section peak blueshift in all cases analyzed. Moreover, our calculations imply that the nanoparticle in the gap between prisms strongly influences the dependence of spectral properties on the radius curvature.
只有考虑到在纳米尺度上发生的现象，才能开发光子器件并理解其工作原理。等离子体结构的光学性质取决于其几何参数，并且对这些参数很敏感。最近，已经提出了许多制备纳米结构的先进方法；然而，几何参数仍然不准确。数值模拟为分析等离子体纳米结构提供了一个强大的工具。据我们所知，关于具有圆形边缘的单个纳米棱镜和纳米棱镜二聚体（即所谓的领结结构）的近场和远场特性的论文并不多。为此，使用了在CST微波工作室中实现的有限积分技术。除了边缘倒圆之外，还研究了通过在棱镜之间的间隙中放置球形纳米颗粒实现的对共振模式的额外修改。数值模拟结果表明，曲率边缘的半径强烈影响等离子体峰的定位，并且这种影响在等离子体器件设计中不能被忽略。在所有分析的情况下，边缘曲率半径的增加都会导致主要消光截面峰的蓝移。此外，我们的计算表明，棱镜之间间隙中的纳米颗粒强烈影响光谱特性对曲率半径的依赖性。
