Tuning of Reciprocal Plasmonic Metasurface Resonances by Ultra-Thin Conformal Coatings
Tuning of Reciprocal Plasmonic Metasurface Resonances by Ultra-Thin Conformal Coatings
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DOI：
10.3390/opt3010009
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
Micheal McLamb;Seran Park;V. Stinson;Yanzeng Li;Nuren Shuchi;G. Boreman;T. Hofmann
中科院分区：
文献类型：
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作者：
Micheal McLamb;Seran Park;V. Stinson;Yanzeng Li;Nuren Shuchi;G. Boreman;T. Hofmann
超材料，在完美的吸收体的形式，最近受到关注的传感和光捕获应用。这种超材料的制造涉及几个工艺步骤，并且通常会导致非理想性，这限制了超材料的性能。本文提出了一种由两个等离子体超颖表面组成的新型互易等离子体超颖表面结构。这种几何形状通过设计避免了许多常见的制造引起的非理想性，并且通过双光子聚合和基于电子束的金属化的组合来合成。红外反射测量表明，倒易等离子体超颖表面是非常敏感的超薄，保形电介质涂层。这在这里通过使用通过原子层沉积生长的Al2O3示出。据实验观察，增量保形涂层的非晶Al2O3的结果在光谱红移的吸收带的倒易等离子体超颖表面。有限元模型计算证实了实验观察结果，这也表明了互易等离子体超颖表面几何形状对共形介电涂层的强烈敏感性。因此，这些涂层提供了对互易等离子体超颖表面共振进行制造后调谐的可能性，从而使这种新颖的几何形状成为窄带吸收体的理想候选者，这允许成本有效的制造和调谐。
Metamaterials, in the form of perfect absorbers, have recently received attention for sensing and light-harvesting applications. The fabrication of such metamaterials involves several process steps and can often lead to nonidealities, which limit the performance of the metamaterial. A novel reciprocal plasmonic metasurface geometry composed of two plasmonic metasurfaces separated by a dielectric spacer was developed and investigated here. This geometry avoids many common fabrication-induced nonidealities by design and is synthesized by a combination of two-photon polymerization and electron-beam-based metallization. Infrared reflection measurements revealed that the reciprocal plasmonic metasurface is very sensitive to ultra-thin, conformal dielectric coatings. This is shown here by using Al2O3 grown by atomic layer deposition. It was observed experimentally that incremental conformal coatings of amorphous Al2O3 result in a spectral red shift of the absorption band of the reciprocal plasmonic metasurface. The experimental observations were corroborated by finite element model calculations, which also demonstrated a strong sensitivity of the reciprocal plasmonic metasurface geometry to conformal dielectric coatings. These coatings therefore offer the possibility for post-fabrication tuning of the reciprocal plasmonic metasurface resonances, thus rendering this novel geometry as an ideal candidate for narrow-band absorbers, which allow for cost-effective fabrication and tuning.