Decision Making Using Analytic Hierarchy Process for Plasmonic Waveguide Simulated by Finite-Difference Eigenmode Method

Abstract

The thickness and materials of a plasmonic layer play a vital role in identifying the highest confinement loss. The finite-difference Eigenmode method (FDE) and the Analytic Hierarchy Process were used to analyze plasmonic waveguide layers. FDE was applied to single-plasmonic layers (Au, Ag, and Cu) and multi- plasmonic layers (Au/Ag, Au/Cu). Refractive index variation (1.1, 1.2, and 1.3) are used to study the highest loss, full-width half maximum (FWHM), and Figure of merits (FOM). Three waveguide designs in multi-layer thickness are used (10/30, 20/30, and 30/30) nanometers. The waveguide sensitivity results for the single Ag layer are 112 nm/RIU, higher than Au and Cu, 66 nm/RIU, and 71 nm/RIU respectively. The sensitivity result of multi-layers is 100 nm/RIU for Au/Ag and 47nm/RIU for Au/Cu. The maximum absorption in Au is 257.5 a.u. at a thickness of 30 nm, and FWHM is 35.8 for the same thickness. The best option and priority for the waveguide optical characteristics are found using Analytic Hierarchy Process (AHP) was Au rank #1, and priority was 93%, followed by Ag rank #2 at 91% priority. Au/Cu (10/30) thickness rank #5 is the best option and priority 86% in multi-layers results. To the best of our knowledge, there has yet to be a report for analyzing the multi-layer using FDE. Also, AHP-based plasmonic sensors for single and multi-layer types are yet to be presented.