To clarify the nature of photonic band gaps, a series of calculations on two-dimensional photonic crystals is undertaken. Systems that possess a large gap for one polarization and no gap for the other polarization are analyzed. Two features of a photonic crystal that give rise to a large photonic band gap for each polarization, i.e., connectivity and concentration of the dielectric material, ar...

We report the simulation results for impact of nonlinear Kerr effect on band structures of a ‎two dimensional photonic crystal (2D-PhC) with no defect, a PhC based W1-waveguide ‎‎(W1W), and also Coupled-Cavity Waveguides (CCWs). All PhC structres are assumed to a ‎square lattice of constant a made of GaAs rods of radius r=0.2a, in an air background. The ‎numerical simulation was performed using...

During recent years, we have observed a rapidly growing interest in the design and fabrication of novel types of photonic-crystal structures possessing large absolute band gaps. The study of various geometries of three-dimensional photonic crystals and different ways to enlarge their absolute band gaps is a key issue in the physics of periodic dielectric structures, where different polarization...

in this paper, using annular resonator we have designed an adding and dropping filter light based ontwo-dimensional photonic crystals. the shape of ring resonator filter adding and dropping that wehave proposed is race track. this filter has a hexagonal lattice structure of silicon bars withrefractive index 3/46 that is located in the context of air with refractive index 1. transmissionefficien...

We consider periodic multilayers combining ordinary positive index materials and dispersive metamaterials with negative index in some frequency range. These structures can exhibit photonic band gaps which, in contrast with the usual Bragg gaps, are not based on interference mechanisms. We focus on effects produced by the interaction between non-Bragg gaps of different nature: a) the zero averag...

In this paper, the forbidden Photonic Band Gaps (PBGs) of a one-dimensional Photonic Crystal (1D PC) with additional regular layer, t for the constant value of the lattice constant A and at normal incident of light beam were investigated. The additional regular layer was formed from both sides of the high-refractive index layer H. The gap map approach and the Transfer Matrix Method were used fo...

We have designed a new type of optical channel drop filter (CDF) based on two dimensionaltriangular lattice photonic crystals. CDF operation is based on coupling to the photonic crystalwaveguide. The proposed structure is optimized to work as a CDF for obtaining the CDFcharacteristics and band structure of the filter the finite difference time domain (FDTD) method andplane wave expansion (PWE) ...

We propose a method to directly visualize the photonic band-structure of micrometer-sized photonic crystals using wide-angle spectroscopy. By extending Fourier imaging spectroscopy sensitivity into the infrared range, we have obtained accurate measurements of the band structures along the high-symmetry directions (X-W-K-L-U) of polymeric three-dimensional, rod-connected diamond photonic crystal...

Periodic layer-by-layer dielectric structures with full three-dimensional photonic band gaps have been designed and fabricated. In contrast to previous layer-by-layer structures the rods in each successive layer are at an angle of 70.5° to each other, achieved by etching both sides of a silicon wafer. Photonic band-structure calculations are utilized to optimize the photonic band gap by varying...

Photonic crystals exhibiting a photonic band gap in both TE and TM polarizations are particularly interesting for a better control of light confinement. The simultaneous achievement of large band gaps in both polarizations requires to reduce the symmetry properties of the photonic crystal lattice. In this letter, we propose two different designs of two-dimensional photonic crystals patterned in...