Preparation and luminescence properties of rare earth doped transparent phosphate glass ceramics
|Course||Condensed Matter Physics|
|Keywords||Rare Earth Er3 / Yb3 Transparent phosphate glass ceramics Upconversion Near-infrared Judd-Ofelt parameters|
Of Er 3 sup> 3 sup> / Yb 3 sup> and of Er doped phosphate glass of Er 3 sup> ion high solubility, of Er 3 sup> / Yb ions in phosphate glass by stimulated emission cross section of a larger, long fluorescence lifetime, the phonon energy is moderate, less prone to fluorescence quenching of Er high efficiency energy transfer between> 3 sup>, upconversion intensity, etc., which in recent years, as a good matrix material of the of 1.5μm microchip lasers and fiber lasers and amplifiers, and has been the utmost concern. These devices have important applications in fiber-optic communications, laser ranging, coherent optical transmission. However, phosphate glass there is less favorable chemical and mechanical stability, thermal conductivity, and the softening temperature is not such as silicate glass, and other shortcomings, and thus also subject to some restrictions on the optical properties and the practical application. Recently the emergence of a new type of laser medium material - rare earth ion doped transparent glass ceramic, glass network structure and glass can be achieved by adjusting the composition and heat treatment conditions, adjust, to reach the controllable crystallization and rare earth in the nano crystal phase the heavily doped purposes. It both some of the advantages of the crystal and glass, having high luminous efficiency, high transmittance, high stability, and the light emitting band tunable performance. And better thermal conductivity and thermal shock resistance, making it more suitable to be used as a high-power laser material. In order to combine the dual advantages of phosphate glass and glass ceramics, high temperature melting method, the ratio through rational design, preparation of a series of Er 3 sup> / Yb 3 sup> doped transparent phosphate glass ceramics, the application of differential thermal analysis (DTA), x-ray diffraction (XRD), transmission electron microscopy (TEM) or scanning electron microscopy (SEM), photoluminescence (PL) spectrum and Judd-Ofelt (JO) theory, the McCumber theory Fuchtbauer-Ladenburg (FL) equation means and methods, a detailed study of each component and heat treatment on the glass ceramic phase composition, microstructure, and luminescent properties of some important conclusions and innovative achievements transparent phosphate glass ceramics further laid the foundation for the development and application of rare earth doped. The main research work and innovative achievements are: Preparation mole group is divided into 37P 2 O 5 -31.4CaO-25.6Na 2 O- 6Al 2 O 3 -0.25Er 2 O 3 -7.5Yb 2 O 3 phosphate glass ceramics, Er 3 sup> ions in the glass and glass ceramic luminescence properties. The XRD tests show the crystal glass ceramic particles YbPO 4 and ErPO 4 , grain size and crystallization rate as the heat treatment time prolonged gradually increase. By PL measurements found that, compared with the glass, Er 3 sup> ions in glass ceramics upconversion luminescence intensity and 1.5μm near-infrared luminescence intensity increases significantly, this crystallization degree and nanometer grain Size variation is relatively consistent. Complete application JO theory, McCumber theory and FL equation calculated and evaluated the spectroscopic parameters before and after the glass crystallization. Recognized crystallization heat treatment of Er into 3 sup> ion YbPO 4 lattice improve the coordination symmetry and order, reduced to its Sites of covalency, leading to the Ω 2 significantly reduced, and thus significantly improve the upconversion luminescence and 1.5μm efficiency of near-infrared light, the effective width and gain parameters, etc.. We also measured the glass ceramics at different temperatures on the conversion and near-infrared light-emitting characteristics, utilize, of Er sup> / Yb 3 sup> Double Mixtureat system level structure and transition process The analysis of the temperature dependence of the emission intensity of the law, as well as multi-phonon relaxation (MPR) theoretical analysis Er 3 sup> ion 4 sup> the the I 13/2 life of the energy level with increasing temperature reduces the reason. These results further optimization of the laser and high gain optical device materials have a guiding role. Prepared and the research of Ce 3 sup> / Er 3 sup> / Yb 3 sup> transparent phosphate glass ceramics doped light-emitting characteristics. Through of Er 3 sup> and Ce found that the introduction of Ce 3 sup> sup> between energy transfer the (Er 3 sup>: < sup> 4 sup> I 11/2 Ce 3 sup>: 2 sup> F 5/2 → Er < sup> 3 sup>: 4 sup> I 13/2 Ce 3 sup>: 2 sup> F 7 / 2 ), you can accelerate the Er 3 sup> ion from 4 sup> I 11/2 in to 4 sup> I nonradiative transition rate 13/2 energy levels, so as to effectively inhibit phosphate glass ceramics under 975nm laser diode (LD) pumped visible upconversion luminescence improve of Er 3 sup> 1.5μm near-band luminescence properties of Ce 3 sup> / Er 3 sup> / Yb 3 sup> doped transparent phosphate glass ceramics more Suitable for the gain of the dielectric material as the optical fiber amplifiers and lasers. Prepared containing the LiPO 3 the /> single relative and LiPO 3 TiP 2 O 7 composite phase transparent luminous glass ceramic to determine the heat treatment conditions on Er 3 sup> / Yb 3 sup> co-doped phosphate glass grain size, light transmittance, upconversion luminescence and 1.5μm near-infrared luminescence properties impact provides a basis for further study of such rare earth doped transparent phosphate glass ceramics. After crystallization, the upconversion luminescence in the glass-ceramic is significantly enhanced, and further increase with the heat treatment temperature or time extension. Precipitation of nanocrystalline Er 3 sup> ions have a positive impact in the 1.5μm at near-infrared light-emitting emission peaks of Stark splitting, the spectrum widened. By the spectroscopic properties of the test and the calculation of the optical performance parameters show that, compared with the same component glass class glass ceramic, 1.5μm emission bandwidth has a wider, more 1.5μm near-infrared light-emitting intensity and upconversion luminescence intensity. 1.5μm near-infrared fluorescence quality factor σ e × τ mea and gain parameter σ e × Δλ eff are better than ZBLAN glass. For example, a heat treatment at 480 ℃ for 4h samples GCA quality factor and gain parameters ZBLAN glass compared to an increase of nearly 33% and 22%, respectively.