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您的检索式:作者名="Steven H Morgan"
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| 1 | Luminescence of Er^(3+) in Oxyfluoride Transparent Glass-Ceramics显示文摘Erbium doped silicate, germanate, and tellurium-germanate oxyfluoride glasses were prepared in a bulk form. Through appropriate heat treatment of the as-prepared glasses, transparent glass-ceramics (TGCs) were obtained with the formation of β-PbF2∶Er 3+ nanocrystals in the glass matrix were confirmed by X-ray diffraction. Well-defined diffraction peaks were observed in the samples after heat-treatment. The average crystal diameter of these precipitated crystals from full-width at half-maximum (FWHM) of the diffraction peak was estimated to be between 8 and 13 nm. Optical absorption, photoluminescence, and upconversion luminescence were measured on as-prepared glass and glass-ceramics. Luminescence spectra in the TGC samples revealed well-resolved, sharp stark-splitting peaks, which indicates that a majority of Er 3+ ions has been incorporated into the crystalline phase of the nanocrystals. The intensity of the visible and near infrared luminescence mostly increases in TSG compared to that in the as-prepared glass. In 1.53 μm absorption and emission bands, the maximum absorption peak is blue-shifted from 1531 to 1507 nm, whereas the maximum emission peak is red-shifted from 1535 to 1543 nm in TGC, as compared with that in glass. The bandwidth at half-maximum (BWHM) of the emission band is significantly broader in TGC than in glass, which is beneficial to the erbium-doped fiber amplifier (EDFA). Upconversion luminescence was measured using 800 nm near-infrared light excitation. Drastically increased upconversion luminescence was observed from the TGC as compared to that from their corresponding as-prepared glasses. In addition to a strong green emission centered at 545 nm because of 4S 3/2 →4I 15/2 transition and a weaker red emission centered at 662 nm because of 4F 9/2 →4I 15/2 transition, generally seen from the Er 3+ doped glasses, two violet emissions centered at 410 nm because of 2H 9/2 →4I 15/2 transition and centered at 379 nm because of 4G 11/2 →4I 15/2 transition were also observed from the TGC. The increased luminescence was attributed to the decreased effective phonon energy and the increased energy transfer between the excited ions when Er 3+ ions were incorporated into the precipitated β-PbF2 nanocrystals. The results indicated two attractive spectroscopic properties of the Er 3+ doped TGC samples, compared to glass samples, namely a reduced multiphonon decay rate and a reduced inhomogeneous broadening. In addition, these oxyfluoride TGC materials were robust, easy and flexibile to process, and possible to be fabricated in the fiber form for device applications. | Akira Ueda Steven H Morgan Richard Mu | 2006 | Journal of Rare Earths2006,24,6: | 7 |
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