Kohandani Reza, Saini Simarjeet Singh
Department of Electrical and Computer Engineering, University of Waterloo, 200 University Ave West, Waterloo, ON N2L 3G1, Canada.
Nanotechnology. 2024 Oct 15;36(1). doi: 10.1088/1361-6528/ad83d7.
In this paper, we present the design and fabrication of a plasmonic metasurface based on titanium dioxide (TiO) nanowire arrays integrated with plasmonic layers. The structure is engineered to produce Fano resonances within the visible spectrum, resulting from the coupling of localized surface plasmon resonances, lattice modes, and nanowire's optical modes. Experimentally, we show that by tuning the geometrical features of the metasurface, such as the length, diameter, and period of the nanowires, a high-quality factor single peak can be achieved in the reflection spectra, resulting in vivid structural colors in bright field. To our knowledge, this is the first demonstration of such vivid colors with nanowire arrays in bright field reflections. When characterized by refractive index fluids around the refractive index of water, the plasmonic metasurface also showed great potential for biochemical colorimetric sensing. The best design demonstrated a bulk sensitivity of 183 nm/RIU with high Q resonance features and linear changes in color values using image processing.
在本文中，我们展示了一种基于集成了等离子体层的二氧化钛（TiO）纳米线阵列的等离子体超表面的设计与制造。该结构经过精心设计，可在可见光谱范围内产生法诺共振，这是由局域表面等离子体共振、晶格模式和纳米线的光学模式耦合产生的。实验表明，通过调整超表面的几何特征，如纳米线的长度、直径和周期，在反射光谱中可以实现高品质因数的单峰，从而在明场中产生鲜艳的结构色。据我们所知，这是首次在明场反射中用纳米线阵列展示出如此鲜艳的颜色。当用折射率接近水的折射率的流体进行表征时，该等离子体超表面在生化比色传感方面也显示出巨大潜力。最佳设计展示了183 nm/RIU的体灵敏度，具有高Q共振特征，并通过图像处理实现了颜色值的线性变化。
