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Yb, Ho: Gd <sub> X </ Sub> <sub> Of La 1-x </ Sub> Vo <sub> 4 </ Sub> Laser Crystal Growth And Spectroscopic Properties Of The Study

Posted on:2005-05-13Degree:MasterType:Thesis
Country:ChinaCandidate:W XiongFull Text:PDF
GTID:2191360125459414Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
Gadolinium lanthanum vanadate crystal (GdxLa1-xVO4) is a new laser host material based on GdVO4 crystal. It has good laser properties such as large wide absorption band, low threshold and high thermal conductivity, which is same as GdVO4 crystal. GdxLa1-xVO4 crystal is a promising laser material for applications of higher power LD pumping laser.In this article, polycrystalline raw materials were synthesized by liquid-phase reaction method. And the synthesized raw materials were detected by infrared spectrophotometer, differential thermal gravimetric analysis, X-ray powder diffraction method, respectively. Several Ho, Yb: GdxLa1-xVO4 crystals with different concentration of Ho, Yb have been grown by Czochralski method with strict growth control. We can successfully grow excellent Ho, Yb: GdxLa1-xVO4 crystal boules without cracks through the investigation and improvement of the growth conditions. The concentration and the effective segregation coefficients of the doped ions in GdxLa1-xVO4 crystals were detected and analysed by ICP method. The lattice constants, density and the laser damage threshold of the crystal were also determined.After being oriented, cut and polished, the grown crystals were processed into a series of wafers. The polarization and non-polarization absorption spectra and fluorescence spectra of these wafers were measured at room temperature. The fluorescence decay curves were also measured in order to fit the fluorescence lifetime of the corresponding levels. The effect of ion concentration on luminescence and lifetime of Ho3+ ions in GdxLa1-xVO4 host were studied in detail. According to the absorption spectra, the phenomenological intensity parameters Ωλ of Ho3+ ions have been fitted based on the Judd-Ofelt theory. Moreover, the spectral parameters of Ho3+ ions including oscillator strengths PJ,J?, radiative transition probabilities AJ,J?, radiative lifetime τ and integrated emission cross-section Σ have been calculated. From the parameters mentioned above, the laser emission probability of Ho, Yb: GdxLa1-xVO4 crystal was discussed. The up-conversion mechanism of Ho3+ sensitized by Yb3+ ions was discussed. And the efficiencies of energy transfer from Yb3+ to Ho3+ ions were calculated.
Keywords/Search Tags:Laser crystal, Liquid phase reaction, Czochralski method, GdxLa1-xVO4 crystal, Judd-Ofelt theory, Spectral properties, Up-conversion luminescence
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