An enhanced finite difference time domain method for two dimensional Maxwell's equations

An efficient finite-difference time-domain (FDTD) algorithm is built to solve the transverse electric 2D Maxwell's equations with inhomogeneous dielectric media where the electric fields are discontinuous across the dielectric interface. The new algorithm is derived based upon the integral version of the Maxwell's equations as well as the relationship between the electric fields across the interface. It is an improvement over the contour-path effective-permittivity algorithm by including some extra terms in the formulas. The scheme is validated in solving the scattering of a dielectric cylinder with exact solution from Mie theory and is then compared with the above contour-path method, the usual staircase and the volume-average method. The numerical results demonstrate that the new algorithm has achieved significant improvement in accuracy over the other methods. Furthermore, the algorithm has a simple structure and can be merged into any existing FDTD software package very easily

Transient analysis of spectrally asymmetric magnetic photonic crystals with ferromagnetic losses

We analyze transient electromagnetic pulse propagation in spectrally asymmetric magnetic photonic crystals (MPCs) with ferromagnetic losses. MPCs are dispersion-engineered materials consisting of a periodic arrangement of misaligned anisotropic dielectric and ferromagnetic layers that exhibit a stationary inflection point in the (asymmetric) dispersion diagram and unidirectional frozen modes. The analysis is performed via a late-time stable finite-difference time-domain method (FDTD) implemented with perfectly matched layer (PML) absorbing boundary conditions, and extended to handle (simultaneously) dispersive and anisotropic media. The proposed PML-FDTD algorithm is based on a D-H and B-E combined field approach that naturally decouples the FDTD update into two steps, one involving the (anisotropic and dispersive) constitutive material tensors and the other involving Maxwell’s equations in a complex coordinate space (to incorporate the PML). For ferromagnetic layers, a fully dispersive modeling of the permeability tensor is implemented to include magnetic losses in a consistent fashion. The numerical results illustrate some striking properties of MPCs, such as wave slowdown (frozen modes), amplitude increase (pulse compression), and unidirectional characteristics. The numerical model is also used to investigate the sensitivity of the MPC response against excitation (frequency and bandwidth), material (ferromagnetic losses), and geometric (layer misalignment and thickness) parameter variations

Review on Computational Electromagnetics

Computational electromagnetics (CEM) is applied to model the interaction of electromagnetic fields with the objects like antenna, waveguides, aircraft and their environment using Maxwell equations.  In this paper the strength and weakness of various computational electromagnetic techniques are discussed. Performance of various techniques in terms accuracy, memory and computational time for application specific tasks such as modeling RCS (Radar cross section), space applications, thin wires, antenna arrays are presented in this paper

Numerical methods for computing Casimir interactions

We review several different approaches for computing Casimir forces and related fluctuation-induced interactions between bodies of arbitrary shapes and materials. The relationships between this problem and well known computational techniques from classical electromagnetism are emphasized. We also review the basic principles of standard computational methods, categorizing them according to three criteria---choice of problem, basis, and solution technique---that can be used to classify proposals for the Casimir problem as well. In this way, mature classical methods can be exploited to model Casimir physics, with a few important modifications.Comment: 46 pages, 142 references, 5 figures. To appear in upcoming Lecture Notes in Physics book on Casimir Physic