Abstract In this work, we emphasize the importance of cavity geometry along with nanoparticle shape and plasmonic nanogap (based on a nanoparticle on a metallic film (NPOM) design) which plays significant role in understanding the complex plasmonic mode characteristics involving nanoparticle and gap mode resonances. The cross-section imprint of planar cavity on metallic film plays decisive role in near field enhancement properties at similar NP size and plasmonic nanogap conditions for spherical and cubical NPOM systems. By mimicking the NPOM structure to metal-insulator-metal design, we understand the resonant emission differences for the respective plasmonic modes. Influence of dominant and weaker gap mode resonances resulted in an interesting optical behavior (fluctuations in near field enhancement strength) in NP mode in case of cubical nanostructures. By such extensive investigation and interpretation of sub-wavelength complex plasmonic mode characteristics, various practical applications in plasmonics field can be accomplished.

中文翻译：

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腔体几何形状对纳米粒子对镜中等离子体间隙耐受性和各自近场的影响

摘要 在这项工作中，我们强调了腔几何形状以及纳米粒子形状和等离子体纳米间隙（基于金属膜上的纳米粒子 (NPOM) 设计）的重要性，这在理解涉及纳米粒子和间隙模式共振的复杂等离子体模式特征方面起着重要作用。 . 对于球形和立方体 NPOM 系统，在相似的 NP 尺寸和等离子体纳米间隙条件下，金属膜上平面腔的横截面印记对近场增强特性起着决定性作用。通过将 NPOM 结构模仿为金属-绝缘体-金属设计，我们了解了各个等离子体模式的共振发射差异。在立方纳米结构的情况下，主要和较弱的间隙模式共振的影响导致 NP 模式中有趣的光学行为（近场增强强度的波动）。通过对亚波长复等离子体模式特性的这种广泛研究和解释，可以完成等离子体领域的各种实际应用。