A multidimensional, nonlinear finite-difference time-domain (NL-FDTD) simulator, which is constructed from a self-consistent solution of the full-wave vector Maxwell equations and dispersive (Lorentz), nonlinear (finitetime-response Raman and instantaneous Kerr) materials models, is used to study finite-length, corrugated, optical waveguide output couplers and beam steerers. Multiple-cycle, ult...

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...

Our objective is the assessment of the accuracy of a conventional finite-difference time-domain (FDTD) code in the computation of the near- and far-field scattering characteristics of a circular dielectric cylinder. We excite the cylinder with an electric or magnetic line current and demonstrate the failure of the two-dimensional FDTD algorithm to accurately characterize the emission rate and t...

Ribbon cables have been widely used as subsystem interconnections in a large number of digital systems, because they can convey numerous bits of a digital signal simultaneously. In this article, finite difference and finite difference time domain (FDTD) methods are used to analyze and optimize the electrostatic analysis design of ribbon cables, and measurements are used to verify the numerical ...

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...

3D Hybrid Finite Element Finite Difference Time Domain (FE/FDTD) Method is developed and applied to the numerical modeling of antennas. The antenna geometry is modeled using tetrahedral finite element mesh. Pyramidal elements are introduced in the transition from unstructured tetrahedral elements to structured hexahedral elements. The finite element formulation incorporates the excitation of an...

To date, a number of numerical methods, including the popular Finite-Difference Time Domain (FDTD) technique, have been proposed to simulate Ground-Penetrating Radar (GPR) responses. Despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the for...

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...