scholarly journals Optimized 3D Finite-Difference-Time-Domain Algorithm to Model the Plasmonic Properties of Metal Nanoparticles with Near-Unity Accuracy

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 114
Author(s):  
Mehran Rafiee ◽  
Subhash Chandra ◽  
Hind Ahmed ◽  
Sarah J. McCormack
Keyword(s):  
Optical Properties ◽  
Finite Difference ◽  
Metal Nanoparticles ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Experimental Results ◽  
Fdtd Simulation ◽  
Localized Surface Plasmon ◽  
Difference Time

The finite difference time domain (FDTD) method is a grid-based, robust, and straightforward method to model the optical properties of metal nanoparticles (MNPs). Modelling accuracy and optical properties can be enhanced by increasing FDTD grid resolution; however, the resolution of the grid size is limited by the memory and computational requirements. In this paper, a 3D optimized FDTD (OFDTD) was designed and developed, which introduced new FDTD approximation terms based on the physical events occurring during the plasmonic oscillations in MNP. The proposed method not only required ~52% less memory than conventional FDTD, but also reduced the calculation requirements by ~9%. The 3D OFDTD method was used to model and obtain the extinction spectrum, localized surface plasmon resonance (LSPR) frequency, and the electric field enhancement factor (EF) for spherical silver nanoparticles (Ag NPs). The model’s predicted results were compared with traditional FDTD as well as experimental results to validate the model. The OFDTD results were found to be in excellent agreement with the experimental results. The EF accuracy was improved by 74% with respect to FDTD simulation, which helped reaching a near-unity OFDTD accuracy of ~99%. The λLSPR discrepancy reduced from 20 nm to 3 nm. The EF peak position discrepancy improved from ±5.5 nm to only ±0.5 nm.

Towards Reducing Computational Costs of Finite Difference Time Domain Algorithm in Plasmonic Optical Properties Modelling of Metal Nanoparticles

2020 ◽  
Vol 995 ◽  
pp. 203-208
Author(s):  
Mehran Rafiee ◽  
Hind Ahmed ◽  
Subhash Chandra ◽  
Conor Mc Loughlin ◽  
Aaron Glenn ◽  
...  
Keyword(s):  
Optical Properties ◽  
Finite Difference ◽  
Metal Nanoparticles ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Computational Cost ◽  
Computational Costs ◽  
Difference Time ◽  
Simulation Time

Finite difference time domain (FDTD) method is a grid-based, robust and straightforward method to model and study the optical properties of metal nanoparticles (MNPs). However, high computational costs of FDTD including simulation time and memory demand mitigate the interest in this algorithm. In this paper, FDTD algorithm is reviewed and reasons of high computational cost requirement in FDTD are investigated. Computational costs are directly characterised by the resolution and size of FDTD grid (known as Yee grid). High FDTD grid resolution is essentially required in MNPs plasmonic modelling to achieve promising accuracy. This results in increasing the dimension of FDTD operational parameters (stored in FDTD matrices) which increases memory and simulation time required and consumed by the algorithm.

Optical Properties of Two Malposed Silver Triangular Nanocylinder Arrays

2014 ◽  
Vol 548-549 ◽  
pp. 182-186
Author(s):  
Zheng Jie Cai ◽  
Gui Qiang Liu ◽  
Zheng Qi Liu ◽  
Xiang Nan Zhang ◽  
Ying Hu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Finite Difference ◽  
Surface Plasmons ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Localized Surface Plasmons ◽  
Plasmonic Nanostructure ◽  
Potential Applications ◽  
Difference Time

We propose and theoretically study a novel plasmonic nanostructure composed of two malposed silver (Ag) triangular nanocylinder arrays by the finite-difference time-domain (FDTD) method. The excitation of the localized surface plasmons (LSPs) of the metal triangular nanocylinders, and the strong interaction coupling between LSPs contribute to the enhanced transparency in the visible and near-in region (NIR). The transparency response in the proposed nanostructure is modified by changing the gap distances between two adjacent triangular nanocylinders, and the dielectric environments. The tunable enhanced optical transparency of the proposed nanostructure provides potential applications in sensors and plasmonic filters.

scholarly journals From Time-Collocated to Leapfrog Fundamental Schemes for ADI and CDI FDTD Methods

Axioms ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Eng Leong Tan
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Unconditionally Stable ◽  
Alternating Direction Implicit ◽  
One Dimensional ◽  
Alternating Direction ◽  
Fdtd Methods ◽  
Difference Time

The leapfrog schemes have been developed for unconditionally stable alternating-direction implicit (ADI) finite-difference time-domain (FDTD) method, and recently the complying-divergence implicit (CDI) FDTD method. In this paper, the formulations from time-collocated to leapfrog fundamental schemes are presented for ADI and CDI FDTD methods. For the ADI FDTD method, the time-collocated fundamental schemes are implemented using implicit E-E and E-H update procedures, which comprise simple and concise right-hand sides (RHS) in their update equations. From the fundamental implicit E-H scheme, the leapfrog ADI FDTD method is formulated in conventional form, whose RHS are simplified into the leapfrog fundamental scheme with reduced operations and improved efficiency. For the CDI FDTD method, the time-collocated fundamental scheme is presented based on locally one-dimensional (LOD) FDTD method with complying divergence. The formulations from time-collocated to leapfrog schemes are provided, which result in the leapfrog fundamental scheme for CDI FDTD method. Based on their fundamental forms, further insights are given into the relations of leapfrog fundamental schemes for ADI and CDI FDTD methods. The time-collocated fundamental schemes require considerably fewer operations than all conventional ADI, LOD and leapfrog ADI FDTD methods, while the leapfrog fundamental schemes for ADI and CDI FDTD methods constitute the most efficient implicit FDTD schemes to date.

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