| In the past decades, light emission at 1.5μm waveband attracted much attention because it can be applied to laser detection, medical diagnosis and optical fiber communication. Laser diode pumped Er-Yb-codoped solid state lasers have many advantages, such as compact structure, high efficiency, low cost, so it is the best choice to get 1.5μm light source. Among many laser materials, phosphate glass is considered to be an ideal candidate for its high Er3+/Yb3+ions solubility, high energy transfer efficiency from Yb3+ to Er3+, and high phonon energy. However, it also has some short points, such as poor thermal conductivity and poor mechanical property, which restricts its application and needs to be improved. Recently, rare earth (RE) doped transparent glass ceramics have been widely investigated since they exhibit the advantages of both glass and ceramic, especially better thermal conductivity and thermal shock, which make them more suitable to be laser materials for high-power devices.This dissertation has researched the optical spectra properties of Er3+/Yb3+-codoped phosphate glass and glass ceramic. In chapter one, we introduced the research significances of 1.5μm solid state laser, and the development of Er-doped transparent glass ceramics. In chapter two, we introduced some experiment and theoretical methods, which is necessary for optical spectra investigations.Then, we studied the luminescence behavior of Er3+/Yb3+-codoped phosphate glass in details through three sections, and those are:luminescence mechanism, concentration and temperature. We fabricated P-Ca-Na glass using high temperature melting technique, and its emission cross section is 1.04×10-20 cm2, which is better than that in germinate, tellurite and silicate glasses. The near infrared (NIR) band upconversion (UC) centered at 828nm contains two-photon and three-photon processes, and it was attributed to the transition 4S3/2→4I13/2, which is useful to the 1.54 micron generation although this UC transition process itself is still one of the channels for energy loss. We also discussed the influences of RE ions doping concentrations on the luminescence spectra, and the result shows:when the Er3+ ions concentration is relatively high, radiation trapping will broaden the spectra, which has never been reported in phosphate candidate before; while the Yb3+ concentration is larger, the luminescence is stronger, but it is a challenge for glass fabricating. Next we found when temperature increases, Er3+ luminescence intensity decreases (except the 520nm waveband). Based on the detailed analysis on non-radiative decay probability, we thought this was not the only reason for this phenomenon, another reason may be that the absorption cross section of Yb3+ ions decreases when temperature increases, but this one needs to be verified.Next we compared the luminescence behavior between Er3+/Yb3+ -codoped phosphate glass ceramics and precursor glasses in details. In theory, we analyzed the changes of ions in different energy levels and predicted the variation of their luminescence intensities, In experiment, we fabricated two kinds of glass ceramics, which are P-Ca-Na and P-Li-Ca-Ti-K. XRD spectrum was used to identify the type of nanoparticles, and we also examined their UC and NIR luminescence spectra excited by 980nm laser diode. The results shown that the spectra of glass ceramic had very clear splits (especially in the NIR waveband), indicating the Er3+ ions had been coupled into nanoparticles. And the UC luminescence intensity of glass ceramic was enhanced dramatically, but the NIR intensity decreased a little. Those experiment results are very coincident with our theoretical analysis. Er3+/Yb3+-codoped phosphate glass ceramics with multi emission peaks in 1.5μm waveband have some potential applications in tunable solid state lasers.Finally, we did some prospect to the further work.
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