– In this paper we extend for the case of Maxwell equations the " X-shaped " solutions previously found in the case of scalar (e.g., acoustic) wave equations. Such solutions are localized in theory: i.e., diffraction-free and particle-like (wavelets), in that they maintain their shape as they propagate. In the electromagnetic case they are particularly interesting, since they are expected to be...

Consider a time-harmonic electromagnetic plane wave incident on a perfectly conducting biperiodic surface (crossed grating). The diffraction is modeled as a boundary value problem for the three-dimensional Maxwell equation. The surface is assumed to be a small and smooth deformation of a planar surface. In this paper, a novel approach is developed to solve the inverse diffraction grating proble...

We present a quantitative comparison between two analytic theories for the propagation of electromagnetic waves in periodic dielectric structures. These theories have both been used extensively in the modeling of optical spectra of colloidal crystals exhibiting photonic band gap behavior. We demonstrate that dynamical diffraction theory is equivalent to the scalar wave approximation, in the lim...

High Resolution Interference Microscopy (HRIM) is a technique that allows the characterization of amplitude and phase of electromagnetic wave-fields in the far-field with a spatial accuracy that corresponds to a few nanometers in the object plane. Emphasis is put on the precise determination of topological features in the wave-field, called phase singularities or vortices, which are spatial poi...

The first and second Rayleigh-Sommerfeld diffraction theories, together with the Kirchhoff diffraction theory, are widely used in the formulation of optical diffraction problems [ 1 ]. They arise in the context of the half-space boundary-value problem of scalar wave theory; all sources of the optical field are assumed to be located in the Z~< 0 half-space, and the Z > 0 half-space is taken to b...

In this paper, we study two different Graded Index (GRIN) photonic crystal (PC) structures which are named as structure type I and type II. The PC structures are made of the square rod in an air background. To design a GRIN PC structure the lattice constant has been altered in the direction transverse to propagation. We investigated focusing effect             and waveguiding behavior of electr...

The problem of diffraction of an electromagnetic wave by a thick hologram grating can be solved by the famous Kogelnik's coupled-wave theory (CWT) to a very high degree of accuracy. We confirm this finding by comparing the CWT and the exact result for a typical example and propose an explanation in terms of perturbation theory. To this end we formulate the problem of diffraction as a matrix pro...

Photonic crystals with periodic arrangement of dielectric media can exhibit forbidden gaps in electromagnetic wave bands through Bragg diffraction (Ohtaka; 1979, Yablonovitch; 1987, John; 1987, Temelkuran; 2000). The prohibited frequency ranges are especially called photonic band gaps. If the periodicity is changed locally by introducing a defect, localized modes appear in the band gap (Ho; 199...

The photoconductive terahertz measurement technique was used for measurement of the radiation pattern from thick metal slits. Picosecond pulses were generated and detected by an ultrafast optoelectronic technique using a femtosecond pulse laser and a subpicosecond photoconductor. Photoconductive sampling measurements of the polarization-dependent diffraction of the picosecond electromagnetic pu...

The problem of homogenization, i.e. substantial reduction of the electrical size of the average lattice constant, of electromagnetic left-handed (LH), or more generally composite right/left-handed (CRLH) metamaterials (MTMs), is presented. The undesirable effects of an electrical very large structural unit cell are explained and illustrated by full-wave simulations and experiments with CRLH mus...