Plasmon Mediated Multiphoton Photoemission Microscopy of Au Nanoholes and Nanohole Dimers
Plasmon Mediated Multiphoton Photoemission Microscopy of Au Nanoholes and Nanohole Dimers
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DOI：
10.1021/jp411943f
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发表时间：
2014-03
影响因子：
3.7
通讯作者：
T. Baker;A. Grubisic;D. Nesbitt
中科院分区：
文献类型：
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作者：
T. Baker;A. Grubisic;D. Nesbitt
用超快扫描光电离显微镜(SPIM)研究了纳米球阴影光刻在Au薄膜中形成的“纳米空穴”和“纳米空穴二聚体”的多光子光电子发射，提供了有关新型2D等离子体结构的激光偏振和局域电场增强效应的详细信息。来自各向同性纳米空穴单体的净光电子发射信号(在800 nm处)都低于(d≪λ)和(Ii)与(d≈λ)衍射极限相当，对激光偏振不敏感，尽管较大物种的SPIM图像清楚地显示出垂直于入射激光偏振的纳米空穴切线边缘的电子发射显著增强。对于本质各向异性的等离子体结构，如纳米空穴二聚体，观察到了截然不同的行为。具体地说，当λ=800nm光垂直于二聚体轴线极化时，小的纳米空穴二聚体表现出增强的电子发射，而较大的纳米空穴二聚体产生最佳的电子产量...
Multiphoton photoemission from “nanoholes” and “nanohole dimers” fabricated by nanosphere shadow lithography in a thin Au film are investigated by ultrafast scanning photoionization microscopy (SPIM), which provides detailed information on laser polarization and local electric field enhancement effects for novel 2D plasmonic architectures. The net photoemission signals (at 800 nm) from isotropic nanohole monomers both (i) below (d ≪ λ) and (ii) comparable to (d ≈ λ) the diffraction limit are insensitive to laser polarization, though SPIM images of the larger species clearly reveal strongly enhanced electron emission from nanohole tangent edges perpendicular to incident laser polarization. Fundamentally contrasting behavior is observed for intrinsically anisotropic plasmonic architectures such as nanohole dimers. Specifically, small nanohole dimers reveal enhanced electron emission for λ = 800 nm light polarized perpendicular to the dimer axis, whereas larger nanohole dimers produce optimum electron yields...