Hybridization of plasmonic antenna and cavity modes: Extreme optics of nanoparticle-on-mirror nanogaps
Hybridization of plasmonic antenna and cavity modes: Extreme optics of nanoparticle-on-mirror nanogaps
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DOI：
10.1103/physreva.92.053811
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发表时间：
2015-11-04
影响因子：
2.9
通讯作者：
Aizpurua, J.
中科院分区：
文献类型：
--
作者：
Tserkezis, C.;Esteban, R.;Aizpurua, J.
光学天线中金属纳米GaP的精确结构细节被发现显著地改变了等离子体的响应，产生了可以在散射实验中直接观察到的复杂的电磁模式模式。我们在纳米粒子镜面结构中对这种情况进行了理论分析，形成了对纳米粒子形态的甚至原子尺度的重构敏感的等离子体纳米间隙。我们主要关注纳米粒子的刻面效应，它允许在纳米粒子-镜面几何结构中，在粒子和下面的金属薄膜之间形成超薄的空腔。确定了两组不同的模式：纵向天线模式，它在所有小面宽度范围内都是强辐射和激发的，以及在大小面上产生的横向空腔模式，表现出极端的限制。天线和腔模的相互作用和杂化取决于它们的对称性和纳米带隙边缘的精确形态。从纳米粒子的镜面结构中理解这种复杂的光学结构，对于阐明各种新兴的光化学和光电子过程非常重要。
The precise structural details of metallic nanogaps within optical antennae are found to dramatically modify the plasmonic response, producing a complex pattern of electromagnetic modes that can be directly observed in scattering experiments. We analyze this situation theoretically in the nanoparticle-on-mirror construct, which forms a plasmonic nanogap sensitive to even atomic-scale restructuring of nanoparticle morphology. We focus on the effect of nanoparticle faceting, which allows the formation of ultrathin cavities between the particle and the underlying metallic film in the nanoparticle-on-mirror geometry. Two different sets of modes are identified: longitudinal antenna modes, which are strongly radiative and excited for all facet width ranges, and transverse cavity modes produced at large facets and exhibiting extreme confinement. The interaction and hybridization of antenna and cavity modes is determined by their symmetry and the precise morphology of the nanogap edges. Understanding such complex optics from nanoparticle-on-mirror structures is important to elucidate a wide variety of emerging photochemical and optoelectronic processes.