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...

Collisions play a major role in various models of musical instruments; one particularly interesting case is that of the guitar fretboard, the subject of this paper. Here, the string is modelled including effects of tension modulation, and the distributed collision both with the fretboard and individual frets, and including both effects of free string vibration, and under finger-stopped conditio...

In this contribution an enhanced version of the Finite Difference Time Domain (FDTD) method is used to calculate the field penetration and Specific Absorption Rate (S-AR) pattern for a current sheet applicator used in Hyperthermia treatment. The FDTD method uses modified equations to rigorously model three dimensional dielectric boundaries and a nonuniform grid for computational efficiency. Res...

We investigate the lasing action in coupled multi-row nanopillar waveguides of periodic or fractal structure using the finite difference time domain (FDTD) method, coupled to the laser rate equations. Such devices exhibit band splitting with distinct and controllable supermode formation. We demonstrate that selective lasing into each of the supermodes is possible. The structure acts as a microl...

Wireless communication devices such as tablets are increasing and developing rapidly. The effects of the electromagnetic (EM) waves in the human body from the wireless communication devices have been paid attention. It is well known that the absorption of electromagnetic waves on the human head for a certain period of time may lead to health problems such as headaches, or even worse, significan...

In this paper, a semi-analytical model for the dispersion relation of nanowire lasers is presented. The approach which is based on the multi-conductor transmission line modeling, makes use of the Fourier expansion technique. The cross-section of the nanowire is assumed to be hexagonally-shaped. To determine the accuracy, the model results are compared to the numerical results obtained from FDTD...

A new method modifying the frequency dependent alternating direction implicit finite difference time domain (FD–ADI– FDTD) is presented. The method can improve the accuracy of FD–ADI–FDTD without significant increase of computational costs. The proposed method is validated by numerical tests. Index Terms ADI–FDTD, Debye media, Accuracy of FDTD