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General chemical compositions of prepared glasses with low OH group concentrations are Ge025Ga0 10S0.6, Ge 25Ga,05As05S065 , (TeO2) -(PbCl2)1 with x = 0.4 to 0.6 and (TeO2) -(ZnO)1 with x = 0.75 to 0.80. Samples doped with 500 to 12000 ppm rare earth in weight were prepared. Rare earth doped glasses are homogeneous when RE concentration is less than 3000 ppm. Heterogeneous inclusions arise beyond 1000 ppm RE when doping is made with chloride or oxide.Electron microscopy, absorption and fluorescence measurements have been made. YAG:Nd. Ar, He-Ne lasers were used for excitation of photoluminiscence.The color and the optical quality of the tellurite glasses depend on crucible materials. Rare earth doping results in visible defects or inhomogeneities when concentration is larger than 1000 ppm. The chemical composition and the optical absorption of doped and undoped samples was examined. Fluorescence intensity of Pr and Dy is smaller in these HMO glasses than in the sulfide glasses, this results from higher phonon energy and higher OH concentration. Further development is required for future applications.

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International audienceHighly stable glasses in the (70 − x)Sb2O3[BOND]20Na2O[BOND]10ZnO[BOND]xEr2O3 (x = 0.25, 0.5, and 1.0 mol%) system have been prepared and investigated by UV-Vis-NIR absorption, near infrared photoluminescence and time-resolved spectroscopy. Judd-Ofelt study has been used to determine the intensity parameters (Ω2, Ω4, and Ω6), spontaneous emission probabilities, branching ratios, and radiative lifetimes (τR) related to the corresponding optical transitions of Er3+ ions. Details of the emission at ∼1530 nm and spectroscopic characteristics such as the stimulated emission cross-section (σe), effectiveband width (Δλeff), quantum efficiency, and the optical gain have been summarized, accounting the role of the increased Er content. The obtained results indicate that these new low phonon energy glasses could be used as a laser medium and for optical amplification in the 1.5 µm region. In particular, the composition containing 0.5 mol% Er2O3 exhibits optimal values of Ω2 (4.5 × 10−20 cm2), Δλeff = 57 nm, σe = 7.28 × 10−21 cm2, τmeas (3.36 ms), and quantum efficiency of the 4I13/2 level of Er3+ ions ∼71%

Pd nanoparticles were prepared with reverse micelles of water/AOT/isooctane solution and deposited onto silicon or InP substrates by electrophoresis. A large change of capacitance-voltage characteristics of mercury contacts on a semiconductor was found after Pd deposition. This change could be modified when the Pd deposition is followed by a partial removal of the deposited AOT. The deposited Pd nanoparticles were investigated by optical mictroscopy, SIMS and SEM. Finally, Schottky diodes with barrier height as high as 1.07 eV were prepared by deposition of Pd nanoparticles on n-type InP and by a partial removal of superfluous AOT. These diodes are prospective structures for further testing as hydrogen sensors.