Department of Materials Science and Engineering, McMaster University, 1280 Main Street W. Hamilton ON, L8S 4L7, Canada.
Nano Lett. 2011 Apr 13;11(4):1499-504. doi: 10.1021/nl200634w. Epub 2011 Mar 29.
We detect short-range surface plasmon-polariton (SR-SPP) resonances setup in individual silver nanoantenna structures at high-spatial resolution with a scanning, subnanometer electron probe. Both even and odd multipolar resonant modes are resolved up to sixth order, and we measure their spatial distribution in relation to nanoantenna structures at energies down to 0.55 eV. Fabry-Perot type SR-SPP reflection phase shifts are calculated from direct measurements of antinode spacings in high-resolution plasmonic field maps. We observe resonant SR-SPP antinode bunching at nanoantenna terminals in high-order resonant modes, and antinode shifts in nonhomogeneous local environments. Finally, we achieve good agreement of our experimental SR-SPP maps with numerical calculations of photon excited near fields, using a novel integrated photon excitation geometry.
我们利用扫描式亚纳米电子探针以高空间分辨率探测到单个银纳米天线结构中的短程表面等离激元极化激元（SR-SPP）共振。我们解析了直到第六阶的偶数和奇数多极共振模式，并测量了它们在能量低至 0.55eV 时与纳米天线结构的空间分布关系。我们从高分辨率等离子体场图中节点间距的直接测量中计算出法布里-珀罗型 SR-SPP 反射相移。我们在高阶共振模式中观察到纳米天线末端的共振 SR-SPP 节点聚集，以及非均匀局域环境中的节点移动。最后，我们使用新颖的集成光子激发几何结构，实现了我们的实验 SR-SPP 图谱与光子激发近场的数值计算的良好吻合。
