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Abstract: The comprehensive analysis about heat-generating processes is presented in Er:tellutire glass. The heat fraction of each process and total heat fraction during pumping are investigated. The results show that upconversion is an important heat-generation process and heat problem is serious especially at high Er3+ doping level. The influence of pump power on heat fraction is also discussed. Based on the heat analysis, the optimized doping concentration range of Erbium ions is about 0.5mol% to 1.0mol%. [ABSTRACT FROM AUTHOR]

Abstract: Glass with composition of 51SiO2–24.5Al2O3–23MgO–1.5K2O doped with Co2+ ions was prepared by conventional melting method. The glass sample was heated at 900°C for 360min under atmosphere, and the powder XRD measurement showed that crystalline phase successfully precipitated in the sample. As is compared with standard JCPDS card, the crystalline phase identified as a mixture of zirconium titanate (ZrTiO4) and one of the compounds of magnesium aluminum oxide. The crystallite size was confirmed by transmission electron microscope (TEM) observation; it could be estimated as 30nm in diameter from the TEM image. Based on the area ratio of crystalline phase and residual glass phase, the precipitated crystallite phase volume ratio can be estimated to be not higher than 30% in the Co2+ doped glass ceramic sample. The absorption coefficient at 1.54μm for transparent glass ceramic sample is clearly higher than that in base glass, which can be explained by the fact that Co2+ ions entered into the precipitated nano-sized crystal phase and led to higher absorption coefficient at 1.54μm for tetrahedral coordinated Co2+ ion. Consequently, the Co2+ doped transparent glass ceramic sample with thickness of 0.35mm was used as a saturable absorber for 1.54μm Er-glass laser oscillation, and Q switched pulses with pulse energy of 40mJ, pulse width of 42ns, and peak power of 0.95mW were shown in the experiments. [Copyright &y& Elsevier]

Abstract: In this paper, 2μm emission spectra of Yb–Ho doped fluorophosphate glass are investigated and compared with Yb–Tm–Ho doped fluorophosphate glass. The 2μm emission intensity of Yb–Ho doped fluorophosphate glass is much stronger than that of Yb–Tm–Ho doped fluorophosphate glass, exhibiting that Yb–Ho doping is an appropriate doping system to 2μm application. As the doping concentration of Yb3+ ions in Yb–Ho doped fluorophosphate glass increases, the 2μm emission intensity increases monotonously and possesses a maximum for 10% Yb ions concentration. Therefore, 10% is the optimization of Yb ions doping concentration for 2μm emission. Otherwise, the up-conversion emission of Ho3+ ions is also studied. Combining with the energy transfer processes, the mechanism is discussed. [Copyright &y& Elsevier]