in this paper a new optical channel drop filter (cdf) based on two dimensional (2-d) photonic crystals (phc) with hexagonal shaped structure is proposed and numerically demonstrated by using the finite-difference-time-domain (fdtd) and plane-wave-expansion (pwe) techniques. photonic crystals (phcs) are artificial dielectric nanostructure materials in which a periodic modulation of the material ...

Using hexagonal grids to represent digital images have been studied for more than 40 years. Increased processing capabilities of graphic devices and recent improvements in CCD technology have made hexagonal sampling attractive for practical applications and brought new interests on this topic. The hexagonal structure is considered to be preferable to the rectangular structure due to its higher ...

Hexagonal structure is different from the traditional square structure for image representation. The geometrical arrangement of pixels on hexagonal structure can be described in terms of a hexagonal grid. Uniformly separating image into seven similar copies with a smaller scale has commonly been used for parallel and accurate image processing including image compression on hexagonal structure. ...

waveguides with low confinement loss, low chromatic dispersion, and low nonlinear effects are used in optical communication systems. optical fibers can also be employed in such systems. besides optical fibers, photonic crystal fibers are also highly suitable transmission media for optical communication systems. in this paper, we introduce two new designs of index-guiding photonic crystal fiber ...

2 • 2 hexagonal structure, two frequency bands can be now placed at the same sheet in contrast to the single hexagonal structure where it can appear only one frequency band. This double hexagonal structure can bring improvements for the operators and may allow them to enhance many new factors. In particular, it can be used to enhance security energy and spacial flexibility in cellular networks....

cadmium sulfide nanoparticles were grown using wet chemical method by dissolving the reactants ofcadmium acetate and sodium sulfide in the presence of thioglycerol (tg) as capping agent in ethanolsolvent. different nanoparticle sizes and size distribution were obtained through varying the molaritiesof thioglycerol. at higher tg concentration, synthesis provides a nearly monodisperse nanoparticl...

OF THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science Computer Science The University of New Mexico Albuquerque, New Mexico

the internal structure of dna-ctab and dna-ddab is investigated by a small angel x- ray scattering(saxs) instrument. hexagonal packing of dna was observed for dna complex with ctab, and for ddabcomplex is observed lamellar structure. variations in the internal spacing and degree of long-range ordering aredependent on both surfactant type and concentrations of added salt. when we increased the a...