This paper presents a method for implementing off-grid boundary conditions (BCs) within Yee’s Finite-Difference Time-Domain (FDTD) method, without disturbing the existing uniform mesh or changing the standard FDTD code. Both perfect electric conductor (PEC) and perfect magnetic conductor (PMC) walls are considered. The field values at off-grid virtual boundaries are obtained by extrapolation of...

The finite difference time domain (FDTD) method is commonly used as a numerically accurate way of propagating sound. However, it requires extensive computation. We present a simple method for accelerating FDTD. Specifically, we modify the FDTD update loop to prioritize computation where it is needed most in order to faithfully propagate waves through the simulated space. We estimate for each po...

A hybrid method for analysis of electromagnetic propagation in large unbounded wave structures is presented. This method is a combination of Gaussian Beam Tracing (GBT), Gabor Expansion and the Finite Difference Time Domain method (FDTD). The input field is first expanded into a sum of Gaussian Beams (GBs) using the Gabor Expansion. The resultant GBs are launched inside the system and traced us...

Recently, guiding electromagnetic (EM) waves with a mode at subwavelength scale has attracted great attention, in particular, at optical wavelengths. The related phenomenon is that of surface plasmon polaritons (SPPs) that are bound non-radiative surface waves propagating at metaldielectric interfaces with the fields decaying exponentially away from the interface [1]. Structures supporting such...

We present a new effective permittivity (EP) model to accurately calculate surface plasmons (SPs) using the finite-difference time-domain (FDTD) method. The computational representation of physical structures with curved interfaces causes inherent errors in FDTD calculations, especially when the numerical grid is coarse. Conventional EP models improve the errors, but they are not effective for ...

The explanation of wave behavior upon total internal reflection from a gainy medium has defied consensus for 40 years. We examine this question using both the finite-difference time-domain (FDTD) method and theoretical analyses. FDTD simulations of a localized wave impinging on a gainy half space are based directly on Maxwell's equations and make no underlying assumptions. They reveal that ampl...

With the advent of the current wireless communication revolution and the increase in its applications, the electromagnetic researchers in conjunction with the medical physicians take the initiative of studying the price of this beneficial technical revolution. It is the health hazards due to the electromagnetic radiation on the human body. The most cost efficient mean of studying these effects ...

Using the Finite-Difference-Time-Domain (FDTD) method, we compute the electromagnetic field distribution in and around dielectric media of various shapes and optical properties. With the aid of the constitutive relations, we proceed to compute the bound charge and bound current densities, then employ the Lorentz law of force to determine the distribution of force density within the regions of i...

Ground Penetrating Radar (GPR) is a shallow geophysical method for detecting and locating subsurface targets. The GPR image echo characteristics of complex underground structures can be obtained by carrying out forward modeling research. traditional finite-difference time-domain (FDTD) has low efficiency accuracy. alternating direction implicit FDTD (ADI-FDTD) algorithm surmounts the stability ...