[论文解读] Launching of Visible-Range Hyperbolic Polaritons by Gold Nanoantennas in a natural van der Waals crystal

Clara Clemente-Marcuello, Haozhe Tong+3 more|arXiv (Cornell University)|Feb 9, 2026

Plasmonic and Surface Plasmon Research被引用 0

一句话总结

论文展示了在 MoOCl2 上使用金棒纳米天线在可见波段激发双曲线极化等离子体极化子，实现面内各向异性模态激发、强场约束以及角度相关吸收。

ABSTRACT

Anisotropic van der Waals materials provide a powerful platform for nanoscale optoelectronics, enabling strong light$-$matter interaction and deep electromagnetic field confinement mediated by polaritons, hybrid light$-$matter excitations with unique dispersion properties. While polaritonic phenomena in van der Waals heterostructures have been extensively explored in the mid-infrared frequency range, their behaviour at the visible frequencies remains largely unexplored, in part due to the lack of knowledge on natural materials supporting anisotropic and highly confined visible-range polaritons. In this context, MoOCl$_2$, an anisotropic van der Waals metal, is particularly interesting, since it supports hyperbolic plasmon polaritons (PPs) that enable directional propagation and subwavelength light compression. Here, we investigate the strategy for launching anisotropic PPs in MoOCl$_2$ in the visible frequency range using gold rod nanoantennas. The nanoantennas, placed on top of the MoOCl$_2$ crystal, excite in-plane anisotropic PP modes, effectively overcoming the momentum mismatch between waves in free-space and nanoscale PPs. We demonstrate a strong electromagnetic field confinement, angle-dependent absorption, and controlled anisotropic PP launching enabled by gold nanoantennas, highlighting the potential of MoOCl$_2$ as a compact platform for nanoscale waveguiding and optical signal processing. By providing a practical antenna-based strategy for exciting visible-range PPs, this work addresses the lack of compact elements for optical signal manipulation and opens new opportunities for optoelectronic devices based on van der Waals polaritonics.

研究动机与目标

• 探索范德华材料在可见波段极化子与纳米尺度光电子学中的潜力与动机。
• 研究金纳米天线是否能够将自由空间光耦合到 MoOCl2 中的面内各向异性双曲极化极化子。
• 展示对各向异性极化子发射与约束的控制，为潜在的纳米尺度波导与信号处理提供基础。

提出的方法

• 在 MoOCl2 晶体表面放置金棒纳米天线以激发面内双曲极化极化子模。
• 利用天线感应的动量匹配来克服自由空间到极化子动量的错配。
• 表征电磁场约束、角度相关吸收以及各向异性极化子发射。
• 利用 MoOCl2 作为天然范德华材料，在可见波段支持双曲极等离子体极化子。

实验结果

研究问题

• RQ1 金纳米天线是否能够在天然范德华晶体中有效发射可见波段的双曲极化极化子？
• RQ2 天线几何形状对发射极化子的方向性和约束有何影响？
• RQ3 MoOCl2 的各向异性如何影响观察到的极化子色散与传播？
• RQ4 使用该平台在纳米尺度波导和光学信号处理方面有哪些潜在应用？

主要发现

• 金棒纳米天线在 MoOCl2 上在可见波段激发面内各向异性极化子模。
• 该方法实现强电磁场约束和角度相关吸收。
• 通过天线设计可控的各向异性极化子发射，实现定向传播。
• MoOCl2 被突出为在范德华极化子学中用于纳米尺度波导和光学信号处理的紧凑平台。