This article discusses possible solutions to limitations in light extraction efficiency of light-emitting diodes (LEDs) using new types of triple-layer omni-directional reflectors (ODRs). The ODRs have lower mirror losses than metal reflectors and distributed Bragg reflectors (DBRs). High-reflectivity ODRs have been incorporated into AlGaInP LEDs and GaInN LEDs. It is shown that the ODR signifi...

Optically pumped alkali metal atoms currently provide a sensitive solution for magnetic microscopic measurements. As the most practicable plan, Faraday rotation of linearly polarized light is extensively used in spin polarization measurements of alkali metal atoms. In some cases, near-resonant Faraday rotation is applied to improve the sensitivity. However, the near-resonant linearly polarized ...

Shield metal arc welding on the high strength low alloy steels in pipelines to transport natural gas from Iran is of great importance. In this article the effects of annealing heat treatment on properties of multi pass welding in different situations (6-4:30 , 4:30-3 , 3-1:30 , 1:30-12) with 36 in outside diameter is evaluated by chemical,  metallography, tensile, toughness and hardness. Tensil...

Hybrid plasmonic waveguides have achieved rapid advancement in plasmonics, which has given rise to remarkable field enhancement, light harvest, light-transport capabilities, bridging the gap between electronics and photonics by routing and manipulating light at sub-wavelength regions and so on. However, the development of plasmonic waveguides is hindered by lack of devices that can adjust coher...

Light emission during the collision of ions and cluster ions on a metal surface covered by rare gas matrices of variable thickness is reported. The light intensity as a function of distance from the metal surface follows the classical image dipole theory. The spectral signature of the light corresponds to the fluorescence of the neutral cluster species deposited as well as to fragments. The nat...

Phototrophy and chemotrophy are two dominant modes of microbial metabolism. To date, non-phototrophic microorganisms have been excluded from the solar light-centered phototrophic metabolism. Here we report a pathway that demonstrates a role of light in non-phototrophic microbial activity. In lab simulations, visible light-excited photoelectrons from metal oxide, metal sulfide, and iron oxide st...

cuals2  chalcopyrite  nanocrystalline  are  synthesized  with  facile method.  the  heat  arrested  solvothermal  method  for  synthesize nanocrystalline  were  investigated.  the  time  duration  of  synthesis, temperature of solution and metal salts to solvent molar ratio can be parameters  that we are  studied. the nanoparticles were  synthesized with cucl, alcl3 and  thiourea (sc(nh2)2) as ...

introduction: this in vitro study investigates the marginal and internal fit of indirect class ii composite restorations. two different processes for chair-side restorations were compared. in group a, the restorations were fabricated using cad/cam technology (cerec, sirona, germany, bernsheim) and in group b they were made by hand (grandioso inlay system, voco gmbh, germany, cuxhaven). methods:...

Plasmonics is a field of study that explores the interaction of light waves and metallic surfaces, and the resulting electron density waves that can be generated from this interaction. The resulting electron density wave that propagates along the surface of the metal is referred to as a surface plasmon polariton, or a surface plasmon. Surface plasmons present many applications. They can be used...

We report a derivative spectroscopic method for determining insulator-to-semiconductor transition during sol-gel metal-oxide semiconductor formation. When an as-spun sol-gel precursor film is photochemically activated and changes to semiconducting state, the light absorption characteristics of the metal-oxide film is considerable changed particularly in the ultraviolet region. As a result, a pe...