Dynamic Nonlocal Dielectric Metasurfaces: Tuning Collective Lattice Resonances via Substrate-Superstrate Permittivity Contrast
Dynamic Nonlocal Dielectric Metasurfaces: Tuning Collective Lattice Resonances via Substrate-Superstrate Permittivity Contrast
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动态非局域介电超表面：通过基底-上层介电常数对比调节集体晶格共振
DOI：
10.1002/adpr.202300268
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Allayarov I
中科院分区：
文献类型：
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作者：
Allayarov I
与单个纳米结构的局部共振相反，周期性超颖表面中的集体（或非局部）共振，例如表面晶格共振（SLR），可以显着增强光-物质相互作用，导致更高的光谱选择性。这种非局部响应的动态控制是一个新兴的研究领域。虽然已经在等离子体超颖表面中证明了SLR的调谐，但是电介质超颖表面的使用提供了控制反射率和透射率两者的附加条件，具有最小的吸收效应。通常需要接近均匀的环境来保证SLR的激发。在这里，我们提出了理论和实验证明一个实用的策略，在介电超颖表面时，任意的折射率失配被认为是基板和覆盖层之间的调谐的SLR。该方法是基于广义晶格和理论，占基板的存在。通过光流体工艺，利用可改变的覆盖层实现了放置在衬底上的硅超颖表面中的SLR的动态调谐。两个调谐机制被揭示对应于移位和阻尼的SLR，取决于衬底的折射率对比度。所展示的透射和反射的动态操纵可以在电介质超颖表面中用于可调谐光谱选择性、感测或新型显示技术。
Contrary to local resonances of single nanostructures, collective (or nonlocal) resonances in periodic metasurfaces, such as surface lattice resonances (SLRs), can significantly enhance light–matter interaction, leading to higher spectral selectivity. The dynamic control of such nonlocal response represents an emerging field of research. While tuning of SLRs has been demonstrated in plasmonic metasurfaces, the use of dielectric metasurfaces provides additional conditions to control both reflectance and transmittance, with minimum absorption effects. A close‐to‐homogeneous environment is usually required to guarantee the excitation of SLRs. Here, we propose theoretically and demonstrate experimentally a practical strategy for the tuning of SLRs in dielectric metasurfaces when an arbitrary index mismatch is considered between substrate and superstrate. The approach is based on a generalized lattice sum theory that accounts for the presence of a substrate. Dynamic tuning of the SLRs in silicon metasurfaces placed on a substrate is achieved with a changeable superstrate via an optofluidic process. Two tuning mechanisms are revealed corresponding to shifting and damping of the SLR, depending on the superstrate–substrate refractive index contrast. The demonstrated dynamic manipulation of transmission and reflection may be exploited in dielectric metasurfaces for tunable spectral selectivity, sensing, or novel display technologies.