Enhancing Plasmonic Spectral Tunability with Anomalous Material Dispersion.
Enhancing Plasmonic Spectral Tunability with Anomalous Material Dispersion.
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DOI：
10.1021/acs.nanolett.0c03293
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发表时间：
2020-12
期刊：
影响因子：
10.8
通讯作者：
Mengjie Zheng;Yi Yang;Di Zhu;Yiqin Chen;Zhiwen Shu;K. Berggren;M. Soljačić;H. Duan
中科院分区：
文献类型：
--
作者：
Mengjie Zheng;Yi Yang;Di Zhu;Yiqin Chen;Zhiwen Shu;K. Berggren;M. Soljačić;H. Duan
等离子体系统的场限制使得光谱可以在结构变化或环境扰动下调谐，这是包括纳米操纵器、传感器和彩色显示器在内的各种应用的原理。在这里，我们提出并证明了具有反常色散的材料，如可见光中的Ge，改善了光谱的可调性。我们用一幅半解析导模图像介绍我们的方案。使用Ge基薄膜(Ag/Au)耦合的GaP等离子体共振腔，我们实现了两种结构，并通过单粒子暗场散射、系综反射和颜色产生展示了改进的可调性。我们观察到，与可见光中的正常色散材料Si相比，Ge纳米盘的可调谐性提高了三倍。由反向制造的Ge-Ag谐振器制成的大型阵列系统的结构颜色产生显示出很宽的色域。我们的结果引入了反常的材料色散作为一个额外的自由度来设计等离子体激元系统的光谱可调谐，特别是与主动可调谐的等离子体激元和亚表面有关。
The field confinement of plasmonic systems enables spectral tunability under structural variations or environmental perturbations, which is the principle for various applications including nanorulers, sensors, and color displays. Here, we propose and demonstrate that materials with anomalous dispersion, such as Ge in the visible, improve spectral tunability. We introduce our proposal with a semianalytical guided mode picture. Using Ge-based film (Ag/Au)-coupled gap plasmon resonators, we implement two architectures and demonstrate the improved tunability with single-particle dark-field scattering, ensemble reflection, and color generation. We observe three-fold enhancement of tunability with Ge nanodisks compared with that of Si, a normal-dispersion material in the visible. The structural color generation of large array systems, made of inversely fabricated Ge-Ag resonators, exhibits a wide gamut. Our results introduce anomalous material dispersion as an extra degree of freedom to engineer the spectral tunability of plasmonic systems, especially relevant for actively tunable plasmonics and metasurfaces.