Plasmonic nanoantennas are typically designed with RF-inspired rigorous parametric optimization processes that lack proper physical insights. In this article, we demonstrate a systematic optimization approach for nanoantennas based on characteristic mode analysis (CMA). A complex geometry, designated as split-ring two-wire antenna (SRA), is selected and optimized using the CMA technique. CMA identifies the dominant modes of the structure at the frequency of interest as well as explains the dependence of the modes on the structure’s shape, size and material properties. These insights from CMA have been used in this study to efficiently optimize SRA shape, size, and material which yield more than 700% near-field intensity enhancement (NFIE) at the desired operating frequency. This proposed CMA-based optimization method can be adapted easily for many other nanoantenna applications, facilitating the development of improved nanostructures.

中文翻译：

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使用特征模式分析优化等离子体纳米天线

等离子纳米天线通常采用受 RF 启发的严格参数优化过程进行设计，但缺乏适当的物理洞察力。在本文中，我们展示了一种基于特征模式分析 (CMA) 的纳米天线系统优化方法。使用 CMA 技术选择并优化了一种复杂的几何形状，称为裂环两线天线 (SRA)。CMA 在感兴趣的频率下识别结构的主要模式，并解释模式对结构形状、尺寸和材料特性的依赖性。CMA 的这些见解已在本研究中用于有效优化 SRA 形状、尺寸和材料，从而在所需的工作频率下产生超过 700% 的近场强度增强 (NFIE)。