Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

M Samak,Mohd Zan,Muhammad Kashif,A Bakar

doi:10.3390/s16040506

Abstract

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD)-FDTD method has similar numerical equation properties, which should be calculated as in the previous method. Generally, a small number of arithmetic processes, which result in a shorter simulation time, are desired. The alternating direction implicit technique can be considered a significant step forward for improving the efficiency of unconditionally stable FDTD schemes. This comparative study shows that the local one-dimensional method had minimum relative error ranges of less than 40% for analytical frequencies above 42.85 GHz, and the same accuracy was generated by both methods.

Highlights

The electrons on differently charged metal boundaries can exhibit clear coherent fluctuations that are confined to both boundary sides of an optical waveguide sensor (OWS)
A surface plasmon resonance (SPR) wave is a wave that propagates along both metallic surfaces and in certain dielectric materials
In the inhomogeneous waveguide case, half of the cavity is occupied by a dielectric material with a relative permittivity of εr = 64, and the other half is occupied by air

Summary

Introduction

The electrons on differently charged metal boundaries can exhibit clear coherent fluctuations that are confined to both boundary sides of an optical waveguide sensor (OWS). A surface plasmon resonance (SPR) wave is a wave that propagates along both metallic surfaces and in certain dielectric materials. A plasmon wave’s electric field reaches its peak value at the surface and decays evanescently away from the surface. The plasmon wave’s properties include high sensitivity to any changes in a device’s geometry or the refractive index of the material. Surface plasmons are increasingly popular due to the interaction between light and matter, which is controlled by patterned structures. The micro-integrated sensor normalizes the employed optical signals to the reference sensing channels based on the refractive index with accurate resolution and increased stability

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Conclusion