Green and red up-conversion emissions and thermometric application of Er^(3+) -doped silicate glass

The green and red up-conversion emissions centred at about 534, 549 and 663 nm of wavelength, corresponding respectively to the ^2H11/2 → ^4I15/2, ^4S3/2 → ^4I15/2 and ^4F9/2 → ^4I15/2 transitions of Er^3＋ ions, have been observed for the Er^3＋-doped silicate glass excited by a 978 nm semiconductor laser beam. Excitation power dependent behaviour of the up-conversion emission intensity indicates that a two-photon absorption up-conversion process is responsible for the green and red up-conversion emissions. The temperature dependence of the green up-conversion emissions is also studied in a temperature range of 296-673 K, which shows that Er^3＋-doped silicate glass can be used as a sensor in high-temperature measurement.

Properties of Local Structure Surrounding Eu^(3+)Ion in Various Niobate-Silicate Glasses

A Series of niobate silicate glasses doped with Eu 3+ ions were prepared. The emission, phonon side band spectra, fluorescence line narrowing spectroscopy and fluorescence lifetimes in these glasses were studied. The intensity parameters and crystal field parameter of Eu 3+ were obtained. The results indicate that the intensity ratio of the electric dipole to magnetic dipole transition and the intensity parameter Ω 2 increase with the increasing concentration of Nb 2O 5, indicating that the symmetry becomes lower, the Eu O bonds become stronger and the covalency of Eu O bond increases. The value of B 20 decreases with the increasing concentration of Nb 2O 5, indicating that the distance between the Eu 3+ ion and oxygen decreases and the Eu O bond becomes strong, corresponding to the results of the former. As the concentration of Nb 2O 5 increases, the electron phonon coupling becomes stronger, thus the nonradiative transition rate of 5D 0 becomes larger and the lifetime of 5D 0 becomes shorter.

Yb^(3+)掺杂硅酸盐玻璃的制备及光谱性质

采用高温熔融工艺制备了Yb3+掺杂硅酸盐玻璃。玻璃的非线性折射率n2小(1.62),转变温度和软化温度低(分别为540℃和585℃)。测试了玻璃的吸收光谱和发射光谱,计算了Yb3+的积分吸收截面和受激发射截面及荧光寿命。吸收光谱曲线表明:吸收区域为850~1 100 nm,主峰位于975 nm,次峰位于908和944 nm;荧光光谱曲线表明:中心峰值为1 010 nm,荧光线宽为65.5 nm。积分吸收截面和受激发射截面及荧光寿命分别为3.44×104pm3,0.710 pm2,1.05 ms。玻璃的常规性能测试和光谱特性研究表明,所制备的玻璃材料能够满足激光玻璃的使用要求。

Yb^(3+)掺杂双包层光子晶体光纤制备研究

本文报道了国内自行研制和制备的以高功率光子晶体光纤激光器为目标的Yb3+掺杂双包层光子晶体光纤。给出了Yb3+掺杂多组分玻璃芯棒和以此为芯的双包层光子晶体光纤的制备流程、工艺和关键技术。对制备的Yb3+掺杂多组分玻璃、双包层光子晶体光纤进行一系列的物理属性、热学和光谱测试,并通过计算分析得到相对优秀的掺杂多组分玻璃配方(Yb3+-(2mol%)-SiO2(70mol%)-MgO-CaO-BaO-Li2O-Al2O3(2mol%))。样品中的Yb3+掺杂双包层光子晶体光纤具有结构规则传光性能良好等优点,为自行开发高功率光子晶体光纤激光器提供材料器件基础。

SiO_2-Bi_2O_3-BaF_2-AlPO_4玻璃掺杂Ho^(3+)/Tm^(3+)/Yb^(3+)的发光性能

以铋硅酸盐玻璃(SiO_2-Bi2O_3-BaF_2-AlPO_4)为基质,通过掺杂Ho^(3+)、Tm^(3+)、Yb^(3+)稀土离子,制备激光波长为2μm的光纤激光器。对玻璃的声子能量、物理和光学性能进行了研究,确定基质配方为50SiO_2-40Bi_2O_3-5BaF_2-5AlPO_4(SBBA,其中化学式前的系数为对应物质的摩尔分数,下同)。在玻璃基质中分别掺杂0.5Ho_2O_3-2.0Yb_2O_3(HY)、0.5Ho_2O_3-0.5Tm_2O_3-2.0Yb_2O_3(0.5HTY)及0.75Ho_2O_3-0.75Tm_2O_3-3.0Yb_2O_3(0.75HTY),研究了980nm激发波长下样品的吸收、发射光谱和Judd-Oflet理论光谱参数。研究发现SBBA-0.75HTY中Ho^(3+)的吸收截面、发射截面(σem)、FWHM(半峰宽)×σem数值最大,分别为7.38×10^(-21)、10.54×10^(-21) cm^2和19.71×10^(-26) cm^3。掺入Tm_2O_3改善了玻璃激光器性能,且当Yb^(3+)/Tm^(3+)/Ho^(3+)物质的量之比一定时,增加稀土离子含量,可加强红外发光及增益效果。

Enhanced 1.8 μm emission in Er^(3+)/Tm^(3+) co-doped lead silicate glasses under different excitations for near infrared laser

A detailed study of the fluorescence emission properties and energy transfer mechanism in Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses was reported. Enhanced near infrared 1.8 μm and visible up-conversion emissions were investigated under 808 and 980 nm excitations, respectively. The energy transfer mechanism between Er^（3＋） and Tm^（3＋） was analyzed according to the absorption spectra, the emission spectra and the level structures of Er^（3＋） and Tm^（3＋）. The energy transfer efficiency between Er^（3＋） and Tm^（3＋） reached 68.1% in the Er^（3＋）/Tm^（3＋） co-doped lead silicate glasses when pumped by 808 nm laser diode. Based on the absorption spectra, the Judd-Ofelt parameters, spontaneous emission probability, absorption and emission cross sections, gain coefficients were calculated and analyzed. It was found that the calculated emission cross section and the maximum gain coefficient around 1.8 μm were 4.9×10^（–21）cm^2 and 1.12 cm^（–1）, respectively. These results indicated that the Er^（3＋）/Tm^（3＋） co-doped lead-silicate glasses had potential application in near infrared lasers.

Tm^(3+)掺杂Bi_2O_3-SiO_2-PbO玻璃的～2μm发光光谱性质

用高温熔融法制备了Tm2O3摩尔掺杂浓度分别为0.1%、0.25%、0.5%、0.75%和1%的33Bi2O3-50SiO2-17PbO玻璃。采用DSC方法对该种玻璃的析晶性能进行研究,发现其Tx–Tg为138℃,说明该玻璃抗析晶性能良好。基于其吸收光谱,采用Judd-Ofelt理论计算了Tm3+离子的J-O参数和部分激发态能级的跃迁几率、荧光寿命和分支比等光谱参量。分析3F4能级寿命随掺杂浓度变化关系,发现产生自淬灭的临界浓度为3.54×1020ions/cm3。用McCumber理论计算在33Bi2O3-50SiO2-17PbO玻璃中Tm3+离子3F4→3H6能级跃迁的吸收截面和发射截面,最大吸收截面和最大受激发射截面分别为3.7×10-21和7.2×10-21cm2。研究结果表明33Bi2O3-50SiO2-17PbO玻璃具有较好的光谱性质,是一种实现~2μm激光的较理想玻璃基质。

Eu^(3+)掺杂铌硅玻璃的微观局域环境特性

研究了Eu3+掺杂铌硅玻璃的5D0发射光谱,其激发谱中7F0 5D2声子边带,荧光窄化谱及5D0能级寿命。并由此计算了强度参数与晶场参数。结果显示5D0 7F2 5D0 7F1发光强度之比与强度参数Ω2随着Nb2O5浓度的增加而增大,表明材料对称性降低,Eu-O键强增加,共价性增强。晶场参数B20随着Nb2O5的浓度增加而减小,同样表明Eu-O键的距离减小,键强增加。随着Nb2O5的浓度增加,电 声子耦合增强,5D0能级的无辐射过程加快,寿命变短。

Tb^3＋掺杂硅酸盐玻璃发光性能的浓度依赖关系

利用高温熔融法制备了不同浓度的Tb3+掺杂硅酸盐玻璃,并分别测量了紫外和X射线激发时的发射光谱。光谱结果表明,不同浓度Tb3+掺杂硅酸盐玻璃在紫外和X射线激发时发光行为具有相似的浓度依赖关系:低浓度Tb4O7掺杂时主要以蓝光(5D3→7FJ)发射为主,而高浓度掺杂时以绿光(5D4→7FJ)发射为主。Tb3+发光强度与掺杂浓度的关系分析表明,5D3的浓度猝灭是电偶极-电偶极相互作用引起的,而5D4的浓度猝灭是交换相互作用引起的。

铒镱共掺锂硅酸盐玻璃的光谱性质

用高温熔融法制备了Er3+ ∶Yb3+ 共掺的锂硅酸盐玻璃 ,在室温下 ,用 976nm半导体激光器泵浦该掺铒玻璃 ,在 15 5 0nm波段实现强的荧光发射 ,中心波长为 1.5 399μm ,荧光半宽高为 5 7.4nm 研究结果表明 ,锂硅酸盐玻璃系统能接受非常高的Er3+ 、Yb3+ 掺杂率 ,有较宽的荧光线宽 ,且具有良好的化学稳定性和热稳定性 。

镱铒共掺硅酸盐玻璃三波段光致发光特性数值分析

考虑两级合作上转换、激发态吸收、交叉弛豫等非线性效应,建立了镱铒共掺硅酸盐玻璃材料9个能级的11个速率方程。唯象地构造了合作上转换系数随镱铒掺杂浓度的变化函数,数值模拟了镱铒共掺硅酸盐玻璃1530,664,549 nm 3个波段的光致发光强度与掺杂浓度、抽运功率的变化关系。计算结果表明:掺铒浓度一定,镱浓度增加时,对于1530 nm荧光而言,有最佳的掺镱浓度,但红光和绿光荧光强度随掺镱浓度始终增强;保持镱铒掺杂浓度不变,抽运功率增加时,3种荧光强度均单调增强,差别在于增幅速率不同,且近红外光强有饱和趋势。计算结果与实验测量相吻合。

掺镱氟铅硅酸盐玻璃光谱性质研究

采用高温熔融法制备了组成为(80-x)SiO2.xPbO.(17～19)(R2O+RF).(1～3)Yb2O3(R=Li、Na、K)(mol%)的掺镱氟铅硅酸盐玻璃,测量了样品的吸收光谱、荧光光谱和荧光寿命,利用McCumber理论计算了该玻璃系统中Yb3+离子2F5/2→2F7/2能级跃迁受激发射截面.结果表明,该玻璃在1013nm处的σemi为0.21×10-20cm2,荧光有效线宽为94.8nm,荧光寿命为2.36ms.激光性能评价结果表明,该玻璃是实现大能量超短脉冲激光的理想材料.

镱铕共掺硅酸盐玻璃光致发光谱及上转换分析

用烧结法制备了镱铕共掺硅酸盐玻璃系列样品.测量了样品在978nm半导体激光器泵浦时光致发光谱,讨论了上转换机制.结果表明:随着镱、铕离子浓度的增加,铕在694nm红光波段光谱强度增强.镱铕离子之间能量传递主要通过合作上转换完成.