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Abstract We investigate the modal properties (effective index and modal gain) of an active, Erbium-doped single-mode slab waveguide made of silica tin-dioxide glass-ceramics on Silica. Completed with a photo-inscribed Bragg grating, such a structure is a good candidate for realizing an optically pumped laser emitter. For total Erbium concentration of 9.84 × 10−4 mol/cm3 and a cross-section (for stimulated transitions) of σ ≈ 2 × 10−25 m2 in a discussed structure, the maximum achievable material gain in DFB with Quarter-Wave phase Shift (QWS-DFB) is σ N tot ≈ 23 m−1. Taking into account the confinement factor, the maximum achievable modal gain, in complex amplitude, over the length of 10 mm is at about (α max L) ≈ 0.09. Highlights • Modal properties of Er3+-doped SiO 2 -SnO 2 glass-ceramics waveguide were investigated. • The threshold properties of a DFB of discussed system were evaluated. • The potential of Er3+-doped SiO 2 -SnO 2 waveguide as a laser source was investigated. [ABSTRACT FROM AUTHOR]

Lead borate glasses doubly doped with Dy 3+ –Tb 3+ were investigated using optical spectroscopy: photoluminescence and decay time measurements. The main green emission band due to the 5 D 4 → 7 F 5 transition of Tb 3+ was observed under excitation of Dy 3+ . The energy transfer process from Dy 3+ to Tb 3+ occurs through nonradiative processes. The energy transfer efficiencies and transfer probabilities as a function of a square of the total rare earth ions concentration using Förster method were calculated. The nonlinear behavior of the energy transfer probability and the luminescence intensity ratio for a higher concentration of acceptor was studied taking into account the possible processes: concentration quenching and partial crystallization of the lead borate glasses. [ABSTRACT FROM AUTHOR]

Abstract Fully amorphous rare earth co-doped barium gallo-germanate glasses were synthesized using the traditional melt quenching-technique. The glass systems were doped with selected pairs of rare earths Dy3+/Ce3+ and Dy3+/Tm3+ ions. To study the spectroscopic properties of gallo-germanate glasses co-doped with Dy3+ and Ln3+ (Ln = Ce, Tm) ions, the luminescence spectra and luminescence decay curves were recorded. It was observed that luminescence bands corresponding to characteristic transitions of Ln3+ (Ln = Ce, Tm) and dysprosium ions are present in the emission spectra measured under direct excitation of Ln3+. The experimental results indicate that energy transfer between dysprosium and cerium/thulium ions is effective. From the emission spectra, the Commission Internationale de I'Eclairage (CIE) chromaticity coordinates (x, y) were calculated in relation to the potential application of gallo-germanate glasses for white LEDs. It has been proved that our glass systems exhibit white emission originating from the simultaneous generation of several bands of Dy3+, Ce3+/Tm3+ under the UV-visible light excitation. Highlights • The rare earth co-doped barium gallo-germanate glasses were synthesized. • The luminescence spectra and luminescence decay curves were registered. • The energy transfer between dysprosium and cerium/thulium ions was examined. • The glass systems exhibit white emission under the UV-visible light excitation. [ABSTRACT FROM AUTHOR]

We describe the synthesis of Pr 3+ /Yb 3+ co-doped and Pr 3+ -doped SiO 2 -Nb 2 O 5 nanocomposites; we also investigate energy transfer processes between the doping ions, which involve UV–Vis to infrared energy conversion. The emission spectra in the near infrared (NIR) region, 900–1650 nm, indicated energy transfer from Pr 3+ to Yb 3+ upon blue excitation of the Pr 3+ ions. UV charge transfer band excitation elicited efficient Yb 3+ emission at about 1.0 µm. The nanocomposite co-doped with 0.5 mol% Pr 3+ and 1.0 mol% Yb 3+ provided maximum energy transfer efficiency. The Pr 3+ ion 3 P 0 excited state lifetime decreased from 11.8 to 3.7 µs as the Yb 3+ ion content in the Yb 3+ /Pr 3+ co-doped nanocomposites increased from 0.25 to 1.0 mol%. This observation attests for energy transfer from Pr 3+ to Yb 3+ ions. On the basis of these results, Pr 3+ /Yb 3+ co-doped SiO 2 -Nb 2 O 5 nanocomposites are promising materials for UV–Vis to NIR energy conversion. [ABSTRACT FROM AUTHOR]