The 30 at.% Ho: BaY2F8 crystals were grown by the Czochralski method, and their spectroscopic properties are analyzed systematically by standard Judd–Ofelt theory. The Judd–Ofelt intensity parameters are estimated ...The 30 at.% Ho: BaY2F8 crystals were grown by the Czochralski method, and their spectroscopic properties are analyzed systematically by standard Judd–Ofelt theory. The Judd–Ofelt intensity parameters are estimated to be Ω2 =6.74 × 10^-20cm^2,Ω4 = 1.20 × 10^-20cm^2, and Ω6= 0.66 × 10^-20cm^2, and the fluorescence branching ratios and radiative lifetimes for a series of excited state manifolds are also determined. The emission cross sections with our measured infrared luminescence spectra, especially important for 4.1 μm, are calculated to be about 4.37 × 10^-21cm^2. The crystal quality is preliminarily tested through a mid-infrared laser emission experiment.展开更多
Fluorozirconate glass containing Euions and chloride ions are prepared by a meltquenching method. The luminescence behavior of Euaffected by Cl ions is investigated. With increasing Cl ion concentration, the luminous ...Fluorozirconate glass containing Euions and chloride ions are prepared by a meltquenching method. The luminescence behavior of Euaffected by Cl ions is investigated. With increasing Cl ion concentration, the luminous intensity of Euis significantly enhanced and the quantum efficiency of fluorozirconate glass is improved. Meanwhile, the intensity parameter ?increases according to the Judd–Ofelt calculation, which indicates the decrease of local symmetry. The average lifetime of Euincreases by introducing the Cl ions. Moreover, we find two kinds of sites for Euions in a glass network by analyzing the fluorescence decay. The distribution of Euions changes with increasing Cl ion concentration.In addition, the excessive Cl ions lead to the separation of the glass phase and the formation of the crystal phase, thus reducing the transmittance dramatically.展开更多
On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ...On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ratios and stimulated emission integrated cross sections between the two excited J manifolds of Tm 3+ , and discussed potentiality for the usage of this crystal as a laser material.展开更多
Using the technique of high-temperature melting, a new Er3+/Yb3+ co-doped fluorophosphate glass was prepared. The absorption and fluorescence spectra were investigated in depth. The effect of Er3+ and Yb3+ concent...Using the technique of high-temperature melting, a new Er3+/Yb3+ co-doped fluorophosphate glass was prepared. The absorption and fluorescence spectra were investigated in depth. The effect of Er3+ and Yb3+ concentration on the spectroscopic properties of the glass sample was also discussed. According to the Judd Ofelt theory, the oscillator strength was computed. The lifetime of 4113/2 level (t-m) of Er3+ ions was 8.23 ms, and the full width at half maximum of the dominating emission peak was 68 nm at 1.53 μm. The large stimulated emission cross section of the Er3+ was calculated by the McCumher theory. The spectroscopic properties of Er3+ ion were compared with those in different glasses. The full width at half maximum and σe are larger than those of other glass hosts, indicating this studied glass may be a potentially useful candidate for high-gain erbium-doped fiber amplifier.展开更多
We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respe...We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respectively. Based on Judd-Ofelt theory, intensity parameters and radiative properties are determined from the absorption and emission spectra. The proposed glass possesses a large fluorescence branching ratio β (21.71%) and a maximum stimulated emission cross-section σem of Er3+:4 I11/2 → 4 I13/2 transition at 2.71 μm (1.04 × 10^-20 cm2). The results indicate that it can be potentially applied in high-power 2.7 μm fiber lasers.展开更多
Intense 2.7-μm emissions are obtained from Er3+/Nd3+ co-doped tellurite glass samples under the 808-nm laser diode excitation. According to the absorption spectra, Judd-Ofelt parameters and radiative transition pro...Intense 2.7-μm emissions are obtained from Er3+/Nd3+ co-doped tellurite glass samples under the 808-nm laser diode excitation. According to the absorption spectra, Judd-Ofelt parameters and radiative transition probabilities are calculated and analyzed using the Judd-Ofelt theory. The spectroscopic properties and energy transfer mechanism between Er3+ and Nd3+ are analyzed. The effects of OH- content on the spectroscopic properties of Er3+/Nd3+ co-doped samples are discussed. The obtained results indicate that Er3+/Nd3+ co-doped tellurite glass can significantly develop optical properties of 2.7-μm emission, if OH- groups can be effectivelv eliminated.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61275146)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120002110066)the Special Program of the Co-construction with Beijing Municipal Government of China(Grant No.20121000302)
文摘The 30 at.% Ho: BaY2F8 crystals were grown by the Czochralski method, and their spectroscopic properties are analyzed systematically by standard Judd–Ofelt theory. The Judd–Ofelt intensity parameters are estimated to be Ω2 =6.74 × 10^-20cm^2,Ω4 = 1.20 × 10^-20cm^2, and Ω6= 0.66 × 10^-20cm^2, and the fluorescence branching ratios and radiative lifetimes for a series of excited state manifolds are also determined. The emission cross sections with our measured infrared luminescence spectra, especially important for 4.1 μm, are calculated to be about 4.37 × 10^-21cm^2. The crystal quality is preliminarily tested through a mid-infrared laser emission experiment.
基金supported by the National High Technology Research and Development Program of China(Grant No.2013AA014201)the Natural Science Foundation of Tianjin,China(Grant Nos.14JCZDJC31200,15JCYBJC16700,and 15JCYBJC16800)+1 种基金the National Key Foundation for Exploring Scientific Instrument of China(Grant No.2014YQ120351)the International Cooperation Program from Science and Technology of Tianjin,China(Grant No.14RCGHGX00872)
文摘Fluorozirconate glass containing Euions and chloride ions are prepared by a meltquenching method. The luminescence behavior of Euaffected by Cl ions is investigated. With increasing Cl ion concentration, the luminous intensity of Euis significantly enhanced and the quantum efficiency of fluorozirconate glass is improved. Meanwhile, the intensity parameter ?increases according to the Judd–Ofelt calculation, which indicates the decrease of local symmetry. The average lifetime of Euincreases by introducing the Cl ions. Moreover, we find two kinds of sites for Euions in a glass network by analyzing the fluorescence decay. The distribution of Euions changes with increasing Cl ion concentration.In addition, the excessive Cl ions lead to the separation of the glass phase and the formation of the crystal phase, thus reducing the transmittance dramatically.
文摘On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ratios and stimulated emission integrated cross sections between the two excited J manifolds of Tm 3+ , and discussed potentiality for the usage of this crystal as a laser material.
基金supported by the National Natural Science Foundation of China (Grant No. 11075026)
文摘Using the technique of high-temperature melting, a new Er3+/Yb3+ co-doped fluorophosphate glass was prepared. The absorption and fluorescence spectra were investigated in depth. The effect of Er3+ and Yb3+ concentration on the spectroscopic properties of the glass sample was also discussed. According to the Judd Ofelt theory, the oscillator strength was computed. The lifetime of 4113/2 level (t-m) of Er3+ ions was 8.23 ms, and the full width at half maximum of the dominating emission peak was 68 nm at 1.53 μm. The large stimulated emission cross section of the Er3+ was calculated by the McCumher theory. The spectroscopic properties of Er3+ ion were compared with those in different glasses. The full width at half maximum and σe are larger than those of other glass hosts, indicating this studied glass may be a potentially useful candidate for high-gain erbium-doped fiber amplifier.
基金supported by the Hundred Talents Program of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(Nos.61475171 and 61177083)+1 种基金the Pujiang Talent Plan(No.14PJ1409200)the Joint Research Project of Chinese Academy of Science and Japan Society for the Promotion of Science(No.GJHZ1412)
文摘We report an Er3+-doped fluorogallate glass with good thermal and chemical stability. The low maximum phonon energy and high mid-infrared (IR) transmittance of the glass are confirmed by Raman and IR spectra, respectively. Based on Judd-Ofelt theory, intensity parameters and radiative properties are determined from the absorption and emission spectra. The proposed glass possesses a large fluorescence branching ratio β (21.71%) and a maximum stimulated emission cross-section σem of Er3+:4 I11/2 → 4 I13/2 transition at 2.71 μm (1.04 × 10^-20 cm2). The results indicate that it can be potentially applied in high-power 2.7 μm fiber lasers.
基金supported by the National Natural Science Foundation of China under Grant No.51172252.
文摘Intense 2.7-μm emissions are obtained from Er3+/Nd3+ co-doped tellurite glass samples under the 808-nm laser diode excitation. According to the absorption spectra, Judd-Ofelt parameters and radiative transition probabilities are calculated and analyzed using the Judd-Ofelt theory. The spectroscopic properties and energy transfer mechanism between Er3+ and Nd3+ are analyzed. The effects of OH- content on the spectroscopic properties of Er3+/Nd3+ co-doped samples are discussed. The obtained results indicate that Er3+/Nd3+ co-doped tellurite glass can significantly develop optical properties of 2.7-μm emission, if OH- groups can be effectivelv eliminated.