Color-tunable and white emission of Tm3+ doped transparent zinc silicate glass-ceramics embedding ZnO nanocrystals

Tm³⁺ doped zinc silicate glass-ceramics composed of SiO₂-Al₂O₃-ZnO-K₂O-Tm₂O₃ embedded with ZnO nanocrystals were successfully fabricated by melt-quenching method with subsequent heat treatment. Tm³⁺ ions and ZnO nanocrystals were introduced as blue and yellow luminescence centers, respectively. The effects of heat treatment, excitation wavelength and Tm³⁺ doping concentration on the photoluminescence behaviors of these glass-ceramics were studied. Short-time (5 minutes) heat treatment was considered as the optimal heat treatment time, which facilitates simultaneously emitting narrow blue peak located at 453 nm and a broad yellow band centered at 580 nm. Blue and yellow emissions could be attributed to the ¹D₂ → ³F₄ transition of Tm³⁺ and Zn_i/O_i-related defect emission of ZnO nanocrystals, respectively. The combination of these two emissions allows the realization of white light emitting in the glass-ceramic samples. Furthermore, tunable luminescent color and chromaticity coordinates, including yellow, white and blue, can be realized by varying the pumping wavelengths as well as the content of Tm³⁺ dopant in the glass matrix. Nearly perfect white light emission with Commission Internationale de l'Eclairage coordinate (x = 0.33, y = 0.32) was achieved for the 0.05 mol% Tm³⁺ doped glass-ceramic embedding ZnO nanocrystals by heat treatment at 750°C for 5 minutes under the excitation of 360 nm. These luminescent glass-ceramics doped with Tm³⁺ ion and ZnO nanocrystals could be a promising candidate for white light emitting devices under near-ultraviolet excitation.     

用Judd—Ofelt理论计算Tm^3＋掺杂的磷酸盐玻璃光谱参数

测试了60P2O5－39RO－1Tm2O3(R=Mg,Ca,Sr,Ba,Zn)和60P2O5－（39－x)BaO-xAl2O3-1Tm2O3(x=0,3,6,9,12,15)(mol%)掺Tm^3 磷酸盐玻璃系列的吸收光谱,确定了Tm^3 离子在磷酸盐玻璃中的能级结构,并根据Judd-Ofelt理论计算了强度参数Ωt(t=2,4,6),给出了Tm^3 离子的振子强度,自发辐射电偶跃迁几率等光谱参数。     

透镜组耦合793nm LD抽运掺Tm~(3+)光纤激光器

为了实现2μm激光高效输出,采用793nm激光二极管端面抽运掺Tm3+光纤激光器的方法设计了抽运光耦合系统,分析了掺Tm3+光纤激光器的交叉弛豫效应及热效应,并进行了相关的实验研究。结果表明,获得耦合系统的耦合效率为84%;当入纤抽运光功率为70W时,获得34W激光输出,斜率效率为59%,中心波长为2001.2nm,光束质量M2≤1.2。该研究结果对掺Tm3+光纤激光器的设计具有指导意义。     

纳秒钬激光碎石系统设计

为了提高结石碎石率和粉碎程度、减小碎石过程中副作用,采用电光调Q技术,设计了高峰值功率输出的纳秒钬激光碎石系统。从冷却温度、透过率、腔长等方面进行了理论分析,在冷却温度22℃、重复频率3Hz、抽运能量200J的条件下进行了实验验证,获得了腔内最大单脉冲能量443mJ、脉宽90ns激光输出的数据。结果表明,该系统可输出高峰值功率的纳秒钬激光,碎石时间短,可粉碎任何成分的结石,一次碎石率高,粉碎程度高。这为下一步产业化打下了基础。     

Up-conversion luminescence of Tm3+/Yb3+ co-doped oxy-fluoride glasses

The oxy-fluorosilicate glasses co-doped with Yb3+/Tm3+ were prepared.The absorption spectra were recorded.The Tm3+ ion showed two absorption bands,with one at 774 nm due to 1G4→3H6 transition and the other at 667 nm due to 1G4→3F4 transition.The energy transfer between Tm3+ ion and Yb3+ ion and the up-conversion fluorescence of Tm3+ ion were investigated using 980 nm LD excitation.The results showed that the blue and red emissions were three-photon absorption processes corresponding with 1G4→3H6 and 1G4→3F4...     

超宽带Er,Tm共掺石英光纤放大器稳态研究

分析了波长为980nm激光抽运下的Er3+,Tm3+共掺石英光纤放大器的工作原理,并根据此工作原理,建立了Er3+与Tm3+之间能量转移过程的数学模型。基于速率方程和功率传输方程,数值模拟了此种光纤放大器稳态工作特性,给出了不同光纤长度、不同输入抽运功率以及不同掺Tm3+浓度下多路光信号放大时输出信号功率谱的变化规律。仿真结果表明,当输入抽运功率为400mW时,Er,Tm共掺石英光纤放大器的3dB带宽可达90nm(比传统掺Er3+光纤放大器的增益带宽大两倍以上),平均增益可达10dB,可用于未来密集复用系统(DWDM)中的宽带放大器件。     

Tm，Yb：NaGd（WO4）2激光晶体生长及光谱性能

采用中频感应提拉法,生长铥镱共掺钨酸钆钠[Tm,Yb：NaGd（WO4）2,Tm,Yb：NGW]激光晶体;讨论了Tm, Yb：NaGd（WO4）2晶体生长工艺参数,获得了合适的晶体生长工艺参数：拉速1~2mm/h,转速20~22r/min,降温速率10℃/h。研究了Tm,Yb：NaGd（WO4）2晶体的荧光光谱。结果表明,在980nm激光的激发下,该晶体在1031mm、1772nm附近获得了较强的荧光发射,分别对应于Yb3+离子的2F5/2→2F7/2能级跃迁以及Tm3+离子的3F4→3H6能级跃迁,1772nm处的半高宽为72nm左右。     

不同掺杂浓度Tm^3＋在YVO4晶体中光吸收各向异性的研究

在室温下测量了５种没的掺杂浓度（６．０ａｔ％,４．０ａｔ％,３．２ａｔ％）ＹＶＯ４;Ｔｍ＾３＋在２００－９００ｎｍ波段的吸收光谱。结果指出,Ｔｍ＾３＋掺杂的ＹＶＯ４晶体光 Ｔｍ＾３＋浓度而变化,每一谱带形状和结构是相似的;而高掺杂浓度Ｔｍ＾３＋的光吸收相对强度比低掺杂浓度的ＹＶＯ４吸收强;不同晶轴ＹＶＯ４晶体吸收质显示出各向异性。观察到在ａ晶轴含π和σ偏振的吸收谱。简要地讨论了Ｔｍ＾３＋,ＹＶＯ４