Showing papers in "Optical Materials in 1998"

TL;DR: A new family of three optical glasses of the following chemical composition with 1 mol% of Nd3+ were prepared to examine the effects of alkali fluorides in unmixed form: 40(NaPO3)6+10BaF2+9ZnF2+,20B2O3+20RF+1NdF3, where RF=LiF, NaF and KF.

TL;DR: In this paper, a simple diffusion model was proposed to account for the essential features of surface relief grating formation based on the anisotropic diffusion of azobenzene-dyes in polymer matrices further to their photoinduced trans-cis isomerization cycles.

TL;DR: In this article, simple correlations between the energy gap, optical electronegativity and the refractive index are given for various classes of materials such as semiconductors, insulators and oxides.

TL;DR: In this article, the emission properties of dye doped polymer microspheres were studied under the weak excitation condition, and the emission exhibits resonant features characteristic to the spherical cavity modes.

TL;DR: In this article, solid state optical space switches based on the thermo-optic (t.o.) effect in polymeric optical waveguides have now reached the commercial stage and the application of these switches is in network protection and network reconfiguration functions for fiber optic communications systems.

TL;DR: In this paper, the authors measured the nonlinear index of refraction (n2) and two-photon absorption (α2) at 1.3 and 1.55 μm, using the Z-scan technique.

TL;DR: In this article, a systematic spectroscopic study of Eu3+ doped yttria powder phosphors is reported, where the effect of modifiers on the 5 D 0 → 7 F 2 transition was investigated under different solvent systems, e.g., ethanol and water.

TL;DR: In this article, the self-assembly of a poly-para-phenylene-ethynylene (PPE) derivative cast onto muscovite mica is investigated by Tapping Mode Scanning Force Microscopy.

TL;DR: In this paper, it was shown that using an ITO glass electrode coated with a self assembled monolayer of an electron accepting phosphonic acid (2-chloroethanephosphonic acid) and aluminium as the electron injecting electrode, the threshold voltage was significantly reduced to the same value as achieved with the less stable Mg:Ag electrode.

TL;DR: In this paper, an overview of the improvement of polymer LED performance at Philips is presented, reflected by lifetimes of many thousands of hours for 8 cm2 devices that operate at daylight visibility under ambient conditions.

TL;DR: In this paper, the optical nonlinear properties of PbS nanoparticles in polyvinyl alcohol (PVA) sol were studied by the Z-scan technique with 50 ps pulses at 530 and 1060 nm, respectively.

TL;DR: In this article, the synthesis and spectroscopic characteristics of a thin film (∼30-90 nm) based on lanthanide europium (III) complexes as the emitter layers, to shift the UV portion of light spectrum into the visible region are discussed.

TL;DR: In this article, the steady state and transient photoluminescence (PL) measurements were carried out on sexithiophene (6T) single crystals, and an analysis of the PL emission and excitation spectra allowed them to establish a general exciton energy scheme of the 6T crystal.

TL;DR: In this paper, a blue-emitting triazole containing co-polymer with high photoluminescence efficiency is described, which acts to enhance the electroluminecence efficiency when used in two layer devices with poly(p-phenylene-vinylene) [PPV] as a hole transporting emitter.

TL;DR: In this article, the Czochralski technique was used to grow Er3+- and Er-3+-, Yb3+ and Yb+-doped scandium silicates Sc2SiO5 and Sc 2Si2O7 and analyzed the spectroscopic properties of these crystals.

TL;DR: In this paper, the structural and optical properties of the sintered CdZnS films have been studied by reflection spectra in the wavelength range 300-600 nm, and the X-ray diffraction pattern of these films for structural analysis is also reported.

TL;DR: Sintered ZnS x Se 1− x films have been prepared in the entire composition range from ZnSe to znS by using the screen printing method as mentioned in this paper, and the wurtzite structure of these films was confirmed by X-ray diffraction analysis of the films.

TL;DR: In this article, vanadium pentoxide thin films were prepared using the electron beam evaporation technique at different oxygen partial pressures keeping the substrate temperature Ts=553 K. The films were characterized by studying their structure and optical properties.

TL;DR: In this paper, a detailed spectroscopic investigation of Lu 3 Al 5 O 12 doped with Ho 3+ has been performed, and the intensity parameters were estimated as Ω 2 =0172±010×10 −20 cm 2, Ω 4 =208±018× 10 −20cm 2, and Ω 6 =192±011×10−20 cm2.

TL;DR: In this paper, the attachment of a fullerene moiety to the conducting polymer backbone is expected to lead to materials with more intimate association of the donor/acceptor sites, and two approaches to attach fullerenes onto polythiophene derivatives have been explored.

TL;DR: In this article, the authors developed new photorefractive media based on hybrid organic-inorganic materials containing a charge transporting (CT) molecule either as side-chain or main-chain substituents on the silica backbone.

TL;DR: The conceptual and technical description of a multi-chamber apparatus for the ultra high vacuum fabrication of highly ordered organic superstructures, recently designed and assembled in our group, is reported in this article.

TL;DR: The infrared properties of β-sialons, Si6−zAlzOzN8−z, prepared by hot, isostatic pressing for nine z-values, as well as a corresponding set of samples containing 1 wt% of yttria have been studied.

TL;DR: In this paper, the synthesis of self-crosslinking fluorinated polymers has been carried out in order to tune refractive index in the range of 1.390 < n < 1.450.

TL;DR: In this article, a wide shoulder and fast lateral growth are characteristics of LaLuO 3 during crystallization onto an iridium rod in Czochralski's configuration, but spontaneous separation of the growing crystal from the melt is a strongly limiting factor for production of large boules.

TL;DR: In this paper, a study of the morphology dependent emission properties of a liquid crystalline polyfluorene in solid thin films is presented, showing that spectral narrowing is strongly dependent on film morphology and the excitation configuration.

TL;DR: In this article, the background absorption spectrum of undoped and doped crystals within the BMO family (Bi 12 MO 20, M=Ge, Si, Ti) was investigated, and dopants were Al, Fe, Cu, Cu/V, and Cr.

TL;DR: In this paper, a combined experimental and theoretical study of the ground and photoexcited optical properties of a model oligomer of PPV, MEH-DSB, was presented.

TL;DR: In this article, the intrinsic rectifying nature of an oriented polymeric material is underlined by the induction of a rectifying current-voltage characteristic, which is proportional to the molecular order.

TL;DR: In this article, an original model accounting for an enhanced nonlinear absorption in concentrated interacting dye solutions is presented, which is induced in the transparency region of the dye solutions and may reach levels as high as using conventional excited state absorption.