This paper describes a 1D Matlab finite difference time-domain (FDTD) code with a graphical user interface for visualization of the time-domain electromagnetic response. The program animates time-domain reflection and transmission of a Gaussian plane wave through one or two homogeneous material slabs. ß2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 136–147, 2001

We study effects of finite height and surrounding material on photonic crystal slabs of oneand two-dimensional photonic crystals with a pseudo-spectral method and finite difference time domain simulation methods. The band gap is shown to be strongly modified by the boundary material. As an application we suggest reflection and guiding of light by patterning the material on top/below the slab.

A novel hybrid Finite Difference Time Domain–Wavelet-Galerkin (FDTD–WG) technique is presented for the accurate representation of electromagnetic field solution in regions of fast field transitions. Its fundamental concept lies on the combination of the robust FDTD method with the Wavelet–Galerkin formulation, which in its turn can efficiently treat highly varying phenomena. The computational d...

During MR procedures majority of the radiofrequency (RF) power transmitted for imaging or spectroscopy is transformed into heat within the patient’s tissue as a result of resistive losses. In this work we evaluate the effect of a wide variety of receive-only insert geometry including cylinders and helmets with different trace widths on spin excitation field and SAR of a 7T TEM transmit coil.

Normally in the finite difference time domain (FDTD) technique, stationaly objects are modeled in a time domain simulation as a field propagates around them, and possibly inside these objects. Tbis paper illustrates a method in which EM fields and a moving object can be modeled using the FDTD technique. By using a techniqne of dielectric approximation and intermediate step field movement, it is...

We demonstrate the feasibility of employing near-field scanning optical microscopy ~NSOM! imaging to simultaneously obtain both the eigenfield distribution and the band-structure information of a photonic crystal. We introduce the NSOM measurement configuration required and simulate the imaging process, with both the tip and the sample included, using three-dimensional finite-difference time-do...

In this paper, an unconditionally stable three-dimensional (3-D) finite-difference time-method (FDTD) is presented where the time step used is no longer restricted by stability but by accuracy. The principle of the alternating direction implicit (ADI) technique that has been used in formulating an unconditionally stable two-dimensional FDTD is applied. Unlike the conventional ADI algorithms, ho...

A technique to incorporate directivity in the Pseudospectral time-domain method (PSTD) for auralization purposes is presented. The Pseudospectral time-domain method is a numerical method for solving the wave equation that requires only two spatial points per wavelength, making it more efficient compared to other wave based methods. The effect of source directivity as well as the head-related di...

In this paper, a method is presented for modeling sound propagation in rooms using a signal processing approach. Low order digital filters are designed to match to sound propagation transfer functions calculated from boundary material and air absorption data. The technique is applied to low frequency, finite difference time domain (FDTD) simulation of room acoustics and to real-time image-sourc...