Showing papers in "Optical Materials in 2009"

TL;DR: In this article, the authors report recent advances in light out-coupling techniques, such as, substrate modification methods, use of scattering medium, micro-lens arrays, microcavity effect, photonic crystals and nano-particles, nano-structures and surface plasmonenhanced techniques that have been implemented to enhance the external extraction efficiency of organic electro-luminescent devices.

TL;DR: In this article, the authors focus on inherent optical properties, governed by composition and the state of the crystallattice, and on the interference of these properties with the microstructural optimization of transparentceramics (e.g., the dependence of the tolerable pore size or grain size on the refractive index).

TL;DR: In this article, a Judd-Ofelt approach has been applied for the f − − f transition of Sm3+ ions to evaluate various intensity parameters (Ω2, Ω4, ǫ6), including variations in intensity parameters, radiative transition probabilities and hypersensitive band positions with composition.

TL;DR: In this paper, the decay curves of Dy 3+ -doped phosphate (P 2 O 5 −+ K 2 O−+ BaO+Al 2 O 3 ) and fluorophosphate (BaO+BaF 2 ǫ+ Al 2 O3 ) glasses have been investigated using the parametric free ion Hamiltonian model.

TL;DR: The optical properties of transparent nanocrystalline zirconia produced using a current activated method were characterized over the entire visible spectrum as mentioned in this paper, and the resolutions of the samples were characterized using standard resolution targets.

TL;DR: In this paper, the particle sizes were monodispersed for the powders obtained from soft chemistry with an average size around 20 nm and polydispersed for the powder from the chemical alloying.

TL;DR: In this paper, a well-dispersed YVO4:Ln(3+) (Ln = Eu, Dy, and Sm) nanocrystals with uniform morphology and size have been synthesized via a facile solvothermal route.

TL;DR: In this article, the effect of free-ion energy level parameters along with calculated energies were determined using the freeion Hamiltonian (H FI ) model using the experimental oscillator strengths to evaluate three phenomenological J-O intensity parameters.

TL;DR: In this paper, the effect of CH3COONa on the formation of microspheres with diameter of 1.5-3μm was investigated, and the upconversion mechanisms were studied through laser power and concentration dependence of upconverted emissions.

TL;DR: Dy3+ and Dy3+/Yb3+ co-doped barium fluoroborate glasses have been synthesized and their luminescence properties have been monitored under UV (355mm) and NIR (976mm) excitations, respectively.

TL;DR: In this article, the angular homogeneity of the light emitted from the color conversion element (CCE) in a phosphor conversion-based white LED was optimized using optical ray tracing.

TL;DR: In this article, an improved crystal ion slicing and bonding technique using polymer adhesive benzocyclobutene was proposed to reproducibly fabricate defect-free LiNbO 3 films with an area of several cm 2.

TL;DR: In this paper, the authors investigated the mechanisms of the solid-state sintering of pure Nd:YAG and of the liquid-phase sinterings of silica-doped Nd-YAG ceramics.

TL;DR: In this article, an optical fiber-based system suitable for monitoring the presence of carbon dioxide, so-called "greenhouse gas", is investigated, where the detection limit of CO2 is established as a function of optical path length.

TL;DR: In this article, the mesophase behavior of bent-shaped monomers was investigated using polarizing optical microscopy, DSC and XRD measurements, and the trans-form of azo compounds (4a-f) showed a strong band in the UV region (355-366), which was attributed to the π-π∗ transition, and a weak band at 455-465 nm due to the n-π ∗ transition.

TL;DR: The analysis of relative and absolute Raman intensity is a very powerful tool, which allows to investigate and characterize the modifications of the structure in covalent bonded compounds, e.g. due to changes of BO 6 octahedra by the substitution of the B site by lanthanides or rare earth elements and the incorporation of protons in the case of high temperature protonic conductors as discussed by the authors.

TL;DR: In this paper, the relationship between factors affecting redox equilibrium, melting temperature, glass composition and carbon addition, and near infrared luminescence (NIR) characteristics of Bi-containing glasses was investigated, and the color center and luminescent center of these glasses were discussed based on redox equilibria.

TL;DR: In this article, Eu-doped CdO thin films (0.4%, 0.5, 0.8, and 1.1%) have been prepared by a vacuum evaporation method on glass and Si wafer substrates.

TL;DR: In this article, the authors showed that Eu 3+ ions are located in the distorted lattice sites near the surface of the ZnO microrods and suggested that the surface defects may act as a step in the process of energy transfer from ZnOs to Eu3+ ions.

TL;DR: In this paper, a comparative spectroscopic investigation of dysprosium-doped YAl3(BO3)4, LiNbO3 single crystals, fluorosilicate glass and fluorogermanate glass was performed with special attention directed to laser potential associated with the 4F9/2→ 6H13/2 transition of Dy3+ near 570mm in the visible.

TL;DR: In this article, a systematic characterization of optical, chemical and thermo-mechanical properties of R2O-MO-TeO2 glasses as function of alkali metals as network modifiers and network intermediate was performed.

TL;DR: In this paper, the upconversion of Er 3+ ions in KBS antimony glass was investigated and three upconverted bands originating from the 2 H 11/2, 4 S 3/2 and 4 F 9/2 transitions were found to be centered at 522, very weak, 536 (green, medium) and 645 (red, strong) nm, respectively.

TL;DR: In this article, the third-order nonlinear optical properties of chalcone derivative doped PMMA films were analyzed using nanosecond Z-scan at 532 nm and the observed nonlinear parameters were comparable with stilbazolieum derivatives for photonics and biophotonics applications.

TL;DR: In this article, the photoluminescence and excitation spectra at room temperature of spinel-type MgGa2O4 with 0.5% and 10.0% of Mn2+ have been studied.

TL;DR: In this article, the Fuchtbauer-Ladenburg (FL) formula was used to calculate the excited state absorption cross sections for 4S3/2→ 4I13/2 and 4S 3/2 → 4I11/2.

TL;DR: In this paper, the influence of thermal treatments on the stability, homogeneity and structure of polycrystalline Eu2+ and Dy3+ doped barium aluminate materials, BaAl2O4:Eu2+,Dy3+, were investigated by X-ray powder diffraction, SEM imaging and infrared spectroscopies as well as by steady state luminescence spectroscopy.

TL;DR: In this article, the lead-free boron silicon bismuthate glasses were investigated in terms of their physical, optical and structural properties, and the physical properties of these glasses have been explored by compositional variation of X-ray diffraction (XRD), differential thermal analysis (DTA) and density.

TL;DR: In this article, LiCAF single crystals were grown by the micro-pulling-down method and optical properties, including absorption coefficient, and photoluminescence emission spectra were measured.

TL;DR: In this paper, the rare earth doped phosphates were synthesized by solid state reaction at high temperature, LaPO 4 :Eu 3+, Gd 3+ by hydrothermal method and LaP 5 O 14 : Eu 3+, Gd3+ by the flux method.

TL;DR: In this article, a trivalent dysprosium (Dy3+) activated magnesium alluminate phosphors were synthesized by high temperature solid state reaction method using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting phosphors.