Abstract We propose a unique random metal nanohemisphere on mirror (NHoM) structure to tune the surface plasmon (SP) resonance in a flexible manner. The SP resonance peak was split into two peaks owing to the strong coupling between the SP mode in the metal nanohemisphere and the mirror image mode generated in the metal substrate. This phenomenon is based on the fact that the strong coupling and the induced electromagnetic effects are similar to those pertaining to the Rabi splitting, Fano resonance, and electromagnetically induced transparency, thus providing quantum effect analogies. These phenomena have recently attracted increased attention and have been studied with nanocavities fabricated with top-down nanotechnologies. Compared with previous reports, NHoM structures can be fabricated in a much easier manner and are tunable in rather wider wavelength regions without nanofabrication technologies. The SP resonance peaks were enhanced, sharpened dramatically, and tuned flexibly, based on the optimization of the thickness of the spacer layer between the metal hemisphere and metal substrate. Experimental results were reproduced and were explained based on finite difference time domain (FDTD) simulations. These phenomena have never been observed previously on similar nanosphere on mirror (NSoM) because nanohemispherical structures were required. The NHoM nanocavity structure has a quality factor >200 that is surprisingly high for the localized SP mode of nanoparticles. Flexible tuning of the SP resonance with the use of NHoM is envisaged to lead to the development of new applications and technologies in the field of plasmonics and nanophotonics.

中文翻译：

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使用镜子上的随机金属纳米半球通过强模式耦合灵活可调的表面等离子体共振

摘要 我们提出了一种独特的随机金属纳米半球镜面 (NHoM) 结构，以灵活的方式调节表面等离子体 (SP) 共振。由于金属纳米半球中的 SP 模式与金属基板中产生的镜像模式之间的强耦合，SP 共振峰被分成两个峰。这种现象是基于这样一个事实，即强耦合和感应电磁效应类似于与 Rabi 分裂、Fano 共振和电磁感应透明相关的那些，因此提供了量子效应类比。这些现象最近引起了越来越多的关注，并且已经用自上而下的纳米技术制造的纳米腔进行了研究。与之前的报道相比，NHoM 结构可以以更简单的方式制造，并且无需纳米制造技术即可在更宽的波长范围内进行调谐。基于金属半球和金属基板之间间隔层厚度的优化，SP共振峰得到增强、显着锐化和灵活调谐。基于有限差分时域 (FDTD) 模拟再现并解释了实验结果。这些现象以前从未在类似的镜面纳米球 (NSoM) 上观察到，因为需要纳米半球结构。NHoM 纳米腔结构具有 >200 的品质因数，对于纳米粒子的局部 SP 模式来说，这是惊人的高。