Davis Timothy J, Vernon Kristy C, Gómez Daniel E
CSIRO Materials Science & Engineering, Private Bag 33, Clayton South, Victoria 3169, Australia.
Opt Express. 2009 Dec 21;17(26):23655-63. doi: 10.1364/OE.17.023655.
The localized surface plasmon resonances in a metallic nanorod are determined using the "electrostatic approximation" and by a finite-difference time-domain numerical solution of Maxwell's equations. The difference between the two methods is related to the effects of re-radiation, or retardation, which is not included in the electrostatic formulation. It is shown that high-order modes in a metallic nanorod can be modeled by both methods, even beyond the point where the electrostatic method is supposed to fail. This suggests that the simple analytical expressions derived from the electrostatic approximation are valid for describing the large range of resonant modes associated with metallic nanoparticles, including dark modes.
金属纳米棒中的局域表面等离子体共振是通过“静电近似”以及麦克斯韦方程组的时域有限差分数值解来确定的。这两种方法之间的差异与再辐射或延迟效应有关，而静电公式中未包含该效应。结果表明，金属纳米棒中的高阶模式可以用这两种方法来建模，甚至在静电方法理应失效的点之后也是如此。这表明从静电近似推导出来的简单解析表达式对于描述与金属纳米颗粒相关的大范围共振模式是有效的，包括暗模式。
