Aluminum-Based Engineered Plasmonic Nanostructures for the Enhanced Refractive Index and Thickness Sensing in Ultraviolet-Visible-Near Infrared Spectral Range
Aluminum-Based Engineered Plasmonic Nanostructures for the Enhanced Refractive Index and Thickness Sensing in Ultraviolet-Visible-Near Infrared Spectral Range
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DOI：
10.2528/pierm19012401
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发表时间：
2019-01-01
影响因子：
1
通讯作者：
Awasthi, Harsh V.
中科院分区：
文献类型：
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作者：
Arora, Pankaj;Awasthi, Harsh V.
我们设计了铝(Al)基周期性等离子体纳米结构来增强折射率和厚度传感，这为表面等离子体共振传感器提供了完整的紫外-可见光-近红外光谱范围。利用严格耦合波分析和有限元全波求解器，通过系统地改变几何参数，设计了镀覆在BK-7玻璃衬底上的均匀薄铝上的铝基周期性纳米结构。利用纳米结构-分析物界面上激发的表面等离激元模式的移动来测量折射率的变化，并用随分析物厚度增加的波导模的数目来捕捉分析物厚度的变化。所提出的周期为400 nm、长宽比为0.1的纳米结构的灵敏度为400 nm/RIU，半高宽为18 nm，优值系数为22。这些铝基等离子体纳米结构具有很高的优值系数、很高的场局部化程度以及维持分析物层流所需的很低的长宽比，因此有可能被用作折射率和厚度传感器。
We engineer Aluminum (Al) based periodic plasmonic nanostructures for enhanced refractive index and thickness sensing, which offer to access complete ultraviolet-visible-near infrared spectral range for surface plasmon resonance sensors. Al-based periodic nanostructures on top of a thin homogeneous Al metal coated on a BK-7 glass substrate were designed by systematic variation of geometrical parameters using Rigorous Coupled Wave Analysis and finite elements full wave solver. The shift in surface plasmon mode excited on the nanostructure-analyte interface was used to measure the variation in refractive index, and the number of waveguide modes with the increase in the thickness of the analyte was used to capture the variation in thickness of the analyte. The proposed nanostructures of period 400 nm and an aspect ratio of 0.1 offered a sensitivity of 400 nm/RIU and full width at half maximum of 18 nm resulting in a figure of merit of 22. These Al-based plasmonic nanostructures have potential to be used as refractive index and thickness sensor due to a high figure of merit, high localization of the field, and very low aspect ratio that is needed to maintain laminar flow of analyte.