Department of Zoology, Faculty of Science, University of Gujrat, Hafiz Hayat Campus, Gujrat, 50700, Pakistan.
Nanotechnology. 2018 Sep 21;29(38):385501. doi: 10.1088/1361-6528/aace9a. Epub 2018 Jun 22.
The current work explores the excitation of surface plasmon polaritons (SPPs) on a one dimensional (1D) silver nano-grating device, simulated on glass substrate, which can sense a very small change in the refractive index of an analyte adjacent to it. The most recent modeling technique finite element analysis is applied in this work by using a COMSOL RF module. The models of 1D grating devices of different slit widths with fixed periodicity and film thickness are simulated. The data is collected and then used to study higher refractive index unit per nanometer (RIU/nm) as well as the effect of the widths of the slits on the RIU. A number of investigations are done by the simulated data, like a dip in the transmission spectra of p-polarized light. This dip is due to SPP resonance with the variation of slit width. Furthermore, the most fascinating part of the research is the COMSOL modeling that provides an opportunity to look into factors affecting higher RIU/nm, while visualizing the cross-sectional view of the grating device and strong electric field enhancement at the surface of the metallic device. When the slit width is almost equal to half of the periodicity of the grating device, SPP resonance increases and it is at maximum for the slit width equal to two-thirds of the periodicity, because the coupling efficiency is at maximum.
当前的工作探索了在一维（1D）银纳米光栅器件上激发表面等离子体激元（SPP）的情况，该器件模拟在玻璃衬底上，可以感应与其相邻的分析物的折射率发生非常小的变化。最近的建模技术有限元分析（FEA）通过使用 COMSOL RF 模块在这项工作中得到了应用。模拟了具有固定周期性和薄膜厚度的不同狭缝宽度的 1D 光栅器件模型。收集数据后，用于研究更高的折射率单位每纳米（RIU/nm）以及狭缝宽度对 RIU 的影响。通过模拟数据进行了多项研究，例如 p 偏振光的透射光谱中的陷波。这种陷波是由于 SPP 与狭缝宽度的变化发生共振而产生的。此外，研究中最吸引人的部分是 COMSOL 建模，它提供了一个机会，可以研究影响更高 RIU/nm 的因素，同时可以可视化光栅器件的横截面视图以及金属器件表面的强电场增强。当狭缝宽度几乎等于光栅器件的周期性的一半时，SPP 共振增加，当狭缝宽度等于周期性的三分之二时，SPP 共振达到最大值，因为耦合效率达到最大值。
