Spectroscopic properties of neodymium-doped tellurite glass fiber

Nd~(3+)-doped tellurite glass and a single mode tellurite glass fiber with a core diameter of 8 μm were prepared in this work. The 1.33-μm emission from the ~4F_(3/2)→~4I_(13/2) transition of Nd~(3+) with a spectral bandwidth of 55 nm in tellurite glass fiber is observed. The lifetime of 164 μs of ~4F_(3/2) level and quantum efficiency of about 100% are obtained.     

Upconversion luminescence of Tm^3＋/Yb^3＋ codoped oxyfluoride glasses

Novel oxyfluoride glasses are developed with the composition of 30SiO2-15Al2O3-28PbF2-22CdF2-0.1TmF3 - xYbF3 - （4.9 - x） AlF3（x=0, 0.5, 1.0, 1.5, 2.0） in tool fraction, Furthermore, the upconversion luminescence characteristics under a 970nm excitation are investigated. Intense blue, red and near infrared luminescences peaked at 453nm, 476nm, 647nm and 789nm, which correspond to the transitions of Tm^3＋： ^1D2 →^3F4, ^1G4 →^3H6, ^1G4 →^3F4, and ^3H4 →^3H6, respectively, are observed. Due to the sensitization of Yb^3＋ ions, all the upconversion luminescence intensities are enhanced considerably with Yb^3＋ concentration increasing. The upconversion mechanisms are discussed based on the energy matching rule and quadratic dependence on excitation power. The results indicate that the dominant mechanism is the excited state absorption for those upconversion emissions.     

具有高机械强度的掺Er~(3 )∶TeO_2-Nb_2O_5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-X)TeO2-XNb2O5(X=5,10,15,20mol%),测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量。利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt(t=2,4,6)和受激发射截面σemi的大小,研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性,并与典型的碲锌钠玻璃(75TeO2-20ZnO-5Na2O)在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

具有高机械强度的掺Er3+∶TeO2-Nb2O5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-XTeO2-XNb2O5(X=5,10,15,20 mol%)，测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量。利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt (t=2, 4, 6)和受激发射截面σemi的大小，研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性，并与典型的碲锌钠玻璃（75TeO2-20ZnO-5Na2O）在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

Broadband 1.5-um emission of erbium-doped TeO_2-WO_3-Nb_2O_5 glass for potential WDM amplifier

Erbium-doped glass showing the wider 1.5-um emission band is reported in a novel oxide system TeO2-WO3-Nb2O5 and their thermal stability and optical properties such as absorption, emission spectra, cross-sections and fluorescence lifetime were investigated. Compared with other glass hosts, the gain bandwidth properties of Er3+ in TWN glass is close to that of bismuth glasses, and larger than those of tellurite, germanate, silicate and phosphate glasses. The broad and flat 4I13/2-4I15/2 emission and the large stimulated emission cross-section of Er3+ ions around 1.5um can be used as host material for potential broadband optical amplifier in the wavelength-division-multiplexing (WDM) network system.     

Amplified spontaneous emission properties of a single mode Er3+-doped tellurite fiber

Spectral characteristics of the amplified spontaneous emission(ASE)from a novel single mode Er3+ doped tellurite fiber with D-type cladding is reported in this letter.When pumped at 980 nm,an ASE source that has nearly a 100-nm flat FWHM bandwidth is obtained with a fiber length of 30-60 cm. Variation of ASE spectra with pump powers and fiber lengths are measured.Output power up to 2.0 mW is obtained with a launched pump power of 660 mW.     

一种新型铒镱共掺碲硅酸盐玻璃的光谱性质及荧光俘获效应研究

用高温熔制法制备了系列Er^3＋／Yb^3＋共掺碲硅酸盐玻璃样品，测试和分析了玻璃样品的吸收光谱、荧光光谱、上转换发光光谱及热稳定性。结果表明：这种玻璃具有较宽的荧光半高宽、较大的受激发射截面，较好的热稳定性。970nm泵浦下该系列玻璃在可见光525，546和658nm这3处存在明显的上转换现象，它们分别由Er^3＋离子^2H11/2→^4 I15/2，4S3/2→^4 I15/2和^4 F9/2→^4 I15/2辐射跃迁产生。另外，测试和讨论了在不同样品厚度下玻璃的光谱特性，如荧光光谱、荧光寿命和上转换发光光谱等。结果表明，荧光俘获效应对Er^3＋离子1．5μm波段荧光及上转换发光都有着较大的影响，并随着玻璃厚度的增加而增大，导致测量值与实际值产生较大的偏差。     

用于1．54μm微片激光器的高Er^3＋／Yb^3＋共掺杂的氟铝酸盐玻璃

本文系统制备了980nm半导体崩浦的应用于1．54μm波段微片激光器的高Er^3 ／Yb^3 共掺杂的氟铝酸盐玻璃。通过玻璃的吸收光谱，发射光谱和上转换荧光光谱的测试，对其光学性质、浓度淬灭及其淬灭机制进行了分析和讨论。当玻璃中Er^3 离子掺杂浓度低于10mol％的情况下，浓度淬灭现象较弱，Er^3 ／Yb^3 共掺杂的氟铝酸盐玻璃在由于Er^3 离子^4 I13／2→4^I 15／2跃迁所引起的1．54μm波段的发射强度比Er^3 单掺杂的氟铝酸盐玻璃中的荧光强度要强。在Er^3 离子掺杂浓度高于10mol％的情况下，由于Er^3 与Yb^3 之间的反能量转移过程，Er^3 ／Yb^3 共掺杂的氟铝酸盐玻璃的1．54μm波段的荧光浓度淬灭效应比Er^3 离子单掺杂的情况下明显。在Er^3 离子掺杂浓度小于10mol％的情况下，实验中发现可获得1．54μm波段高发射效率的Er^3 与Yb^3 离子最佳摩尔浓度掺杂比例约为1：1。     

含纳米晶颗粒的Yb3+/Er3+共掺透明碲酸盐玻璃陶瓷的光谱性质研究

在组成为15Li2O-15Nb2O5-70TeO2-0.1Er2O3-0.4Yb2O3（%, 摩尔分数）的碲酸盐玻璃基础上, 采用两步热处理法制备了透明的含纳米晶颗粒碲酸盐玻璃陶瓷. 通过X射线衍射（XRD）测试表明, 玻璃陶瓷中的晶体颗粒组成为Yb6Te5O19.2或Er6Te5O19.2, 晶粒尺寸约为55 nm. 根据Judd-Ofelt理论计算了Er^3＋离子在基质玻璃和玻璃陶瓷中的光谱参数Ωt（t＝2, 4, 6）以及Er^3＋：4I15/2→4I13/2跃迁自发辐射几率, 根据McCumber理论计算了Er^3＋：4I13/2→4I15/2跃迁的发射截面. 测试了基质玻璃和玻璃陶瓷的拉曼光谱, 对比研究了铒离子在基质玻璃和玻璃陶瓷中1.5 μm处荧光和上转换光谱特性.     

应用于相变存储器的Cu-Ge3Sb2Te5薄膜的结构及相变特性研究

采用磁控溅射法制备了不同Cu含量的Cu-Ge₃Sb₂Te₅薄膜, 原位测试了薄膜电阻与温度的关系, 并利用X射线衍射仪、透射电镜、透过和拉曼光谱仪分别研究了 Cu-Ge₃Sb₂Te₅薄膜的晶体结构、微结构、禁带宽度及成键情况. 结果表明, Cu-Ge₃Sb₂Te₅薄膜的结晶温度和结晶活化能随着Cu含量的增加而增大, Cu的加入有效改善Ge₃Sb₂Te₅薄膜的热稳定性和10年数据保持力. 随着Cu含量的增加, 非晶态Cu-Ge₃Sb₂Te₅薄膜的禁带宽度逐渐减小. 同时, 拉曼峰从129 cm^-1向127 cm^-1处移动, 这是由于Cu–Te极性键振动增强的缘故. Cu-Ge₃Sb₂Te₅结晶为均匀、相互嵌套的六方Cu₂Te和Ge₂Sb₂Te₅相.