Numerical analysis of coupled wedge plasmons in a structure of two metal wedges separated by a gap
Numerical analysis of coupled wedge plasmons in a structure of two metal wedges separated by a gap
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DOI：
10.1063/1.2208291
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发表时间：
2006-07
影响因子：
3.2
通讯作者：
D. Pile;D. Gramotnev;M. Haraguchi;T. Okamoto;M. Fukui
中科院分区：
文献类型：
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作者：
D. Pile;D. Gramotnev;M. Haraguchi;T. Okamoto;M. Fukui
本文介绍了一个强本地化反对称等离子体激元的数值时域有限差分分析的结果，耦合在两个相同的金属楔之间的纳米间隙。色散，耗散，场结构，和存在条件的耦合楔等离子体激元的确定和调查的一个例子的基本耦合模式。结果表明，在一般情况下，存在三个临界楔角和一个临界间隙宽度（楔尖之间的距离）。当差距宽度大于临界间距时，反对称楔形等离子体激元只存在于第一和第二临界角之间以及第三临界角到180°之间的范围内。如果差距宽度小于或等于临界间隔，则第三临界角和第二临界角合并，仅留下一个楔角区间，在该楔角区间内可以存在反对称耦合楔等离子体。本文还研究了圆楔尖的影响，并对圆楔尖的影响进行了讨论。
This paper presents the results of the numerical finite-difference time-domain analysis of a strongly localized antisymmetric plasmon, coupled across a nanogap between two identical metal wedges. Dispersion, dissipation, field structure, and existence conditions of such coupled wedge plasmons are determined and investigated on an example of the fundamental coupled mode. It is shown that in the general case there exist three critical wedge angles and a critical gap width (separation between the wedge tips). If the gap width is larger than the critical separation, then the antisymmetric wedge plasmons can exist only in the ranges between the first and the second critical angles, and between the third critical angle and 180°. If the gap width is smaller or equal to the critical separation, then the third and the second critical angles merge, leaving only one interval of wedge angles within which the antisymmetric coupled wedge plasmons can exist. The effect of rounded wedge tips is also investigated and is s...