Mie共振增强的混合光子结构手性响应

中文摘要 AI 辅助

手性光学响应通过光的手性提供了控制光与物质相互作用的强大途径，在偏振控制、手性传感和非线性光子学中具有至关重要的意义。混合结构通过在同一纳米结构中耦合等离激元场局域与介电Mie共振，可能为工程化此类响应提供新途径。然而，在手性超表面中，杂化在很大程度上仅被视为共振增强的手段，而其主动重塑和反转本征等离激元手性的作用仍未得到充分探索。在此，我们展示了一种混合超表面，其中介电Mie共振介导了等离激元构建单元增强的手性响应。通过将Si纳米圆柱与梯形Au纳米棒耦合，一个弱且模式选择性的等离激元手性种子被重组为两个相反手性的混合共振，产生接近统一的圆二色性并伴随光谱符号翻转。将该机制扩展到非线性领域，相同的混合模式选择性产生了强非线性手性发射和任一符号的接近统一的第三次谐波产生圆二色性。我们相信这些结果确立了等离激元-Mie杂化作为一种新机制，用于在紧凑型超器件中工程化高纯度、符号可切换的线性和非线性手性。

英文摘要

Chiroptical response provides a powerful route to control light-matter interactions through light handedness, with crucial importance in polarization control, chiral sensing, and nonlinear photonics. Hybrid structures may offer a novel route to engineer such responses by coupling plasmonic field localization with dielectric Mie resonances within a single nanostructure. However, in chiral metasurfaces, hybridization has largely been treated as a means of resonance enhancement, while its role in actively reshaping and reversing intrinsic plasmonic chirality remains largely unexplored. Here, we demonstrate a hybrid metasurface in which a dielectric Mie resonance mediates enhanced chiral response of plasmonic building blocks. By coupling a Si nanocylinder to trapezoidal Au nanobars, a weak and mode-selective plasmonic chiral seed is reorganised into two opposite-handed hybrid resonances, producing near-unity circular dichroism with spectral sign flipping. Extending this mechanism to nonlinear regime, the same hybrid-mode selectivity produces strongly nonlinear chiral emission and near-unity third-harmonic generation circular dichroism of either sign. We believe these results establish plasmonic-Mie hybridization as a novel mechanism for engineering high-purity, sign-switchable linear and nonlinear chirality in compact metadevices.

发表机构

• Harbin Institute of Technology（哈尔滨工业大学）
• Australian National University（澳大利亚国立大学）

机构由 AI 辅助整理，请以论文原文为准。

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9 pages, 5 figures