Radiation resistance property of barium gallo-germanate glass doped by Nb2O5

Effects of Nb₂O₅dopant on the radiation response of barium gallo-germanate(BGG)glass are studied mainly by electron paramagnetic resonance and absorption spectroscopy.Owing to the Nb⁵⁺$Nb³⁺interconversion in doped samples,formations of Ge-related non-bridging oxygen hole center and Ge-related electron center defects after g-ray irradiation are inhibited.Thereby,Nb₂O₅dopant can enhance radiation resistance of BGG glass,and 1.0%Nb2O5 concentration is the best.     

Tm~(3+)/Ho~(3+)掺杂碲酸盐玻璃的上转换发光性能与能量转换机制（英文）

采用高温熔融法制备了单掺Tm~(3+)和Tm~(3+)/Ho~(3+)共掺碲酸盐玻璃,测试了808nm激光泵浦下玻璃的红外和上转换荧光光谱。Tm~(3+)/Ho~(3+)共掺碲酸盐玻璃上转换荧光光谱主要由695nm红光、544nm绿光、474nm蓝光和740nm红光四个发光带组成。通过分析样品的光谱性能和能量转换机制,发现很少报道的740nm红光可能是由Tm~(3+):1 D2→3 F2,3能级跃迁产生的。在掺杂0.5 mol%Tm2O3的样品中添加0.3mol%Ho2O3,695nm红光、740nm红光和474nm蓝光等上转换发光强度明显增大,大约分别是单掺0.5mol%Tm2O3样品中发光强度的3倍,2.5倍和14倍。这些情况说明存在着强烈的Ho~(3+)→Tm~(3+)反向能量传递。单掺Tm~(3+)碲酸盐玻璃中1 D2能级(发射740nm红光)上的粒子集居主要来源于合作上转换(CU)过程,而3 F2,3能级(发射695nm红光)上的粒子集居除了来源于CU过程之外,还有740nm红光的发射和1 G4能级上部分粒子的无辐射跃迁(1 G4→3 F2,3)两条途径,因此样品中695nm红光强度明显要大于740nm红光强度。通过交叉驰豫作用CR2和CR3以及反向共振能量转移RET2,Tm~(3+)/Ho~(3+)共掺碲酸盐玻璃中Tm~(3+)的1 G4能级(发射474nm蓝光)上的粒子集居数比单掺Tm~(3+)时出现了净增加。Tm~(3+)的1 G4能级上粒子集居数的增加可能进一步强化了该能级的无辐射跃迁、740nm红光的发射以及CU过程,并进而促使Tm~(3+)的3 F2,3能级上的粒子集居。所以,当Tm~(3+)/Ho~(3+)共掺碲酸盐玻璃与单掺Tm~(3+)碲酸盐玻璃中掺杂相同浓度的Tm~(3+)时,前者的红光和蓝光等上转换荧光强度均比后者要大。本文还研究了Tm~(3+)之间以及Tm~(3+)与Ho~(3+)之间的交叉弛豫和能量传递等效应,并进一步探讨了Tm~(3+)与Ho~(3+)之间的能量转换机制。     

Single-frequency distributed Bragg reflector Tm:YAG ceramic derived all-glass fiber laser at 1.95 μm

A 135 mW single-frequency distributed Bragg reflector fiber laser at 1.95 μm was obtained based on a Tm:YAG ceramic-derived all-glass fiber. The fiber laser achieved an optical signal-to-noise ratio of ～ 77 dB. Moreover, the threshold and linewidth of the single-frequency laser were measured to be 15.4 mW and 4.5 kHz, respectively. In addition, the measured relative intensity noise was less than -140 dB· Hz^-1 at frequencies of over 10 MHz. The results show that the as-drawn Tm:YAG ceramic-derived all-glass fiber is highly promising for ～ 2 μm single-frequency fiber laser applications.     

可紫外激光刻写的掺铒铋硅酸盐玻璃光谱性质研究

报道了可紫外激光刻写的掺铒Na₂O-Bi₂O₃-SiO₂和Na₂O-B₂O₃-Bi₂O₃-SiO₂玻璃的光谱特性. 测量和计算了玻璃的光谱参数，分析、讨论了Bi₂O₃和B₂O₃含量变化对光谱参数的影响.实验表明基质玻璃中Bi₂O₃和B₂O₃含量改变可有效调节掺铒铋硅酸盐玻璃光谱参数.Bi₂O₃和B₂O₃含量增加，玻璃的光吸收和荧光性质改善，但Er³⁺离子的⁴I_13/2能级寿命降低.在B₂O₃含量为40%(Bi₂O₃/SiO₂＝0.67)时，Er³⁺离子峰值发射截面、⁴I_13/2能级的荧光寿命和荧光半高宽分别为8.49×10^－21cm²，0.52ms和78nm.结果表明掺铒铋硅酸盐玻璃是有前途的紫外光敏有源玻璃材料之一.     

Fabrication of crystalline selenium microwire

A method of fabricating selenium(Se) microwire is demonstrated.A multimaterial fiber with amorphous selenium(a-Se) core and multicomponent phosphate glass cladding is drawn by using a conventional optical fiber drawing technique.Then the a-Se core of the fiber is crystallized by a post thermal process at 150 ℃.After the multicomponent phosphate glass cladding is stripped from the multimaterial fiber by marinating the fiber in HF acid solution,a crystalline selenium(c-Se)microwire with high uniformity and smooth surface is obtained.Based on microstructure measurements,the c-Se microwire is identified to consist of most hexagonal state particles and very few trigonal state whiskers.The good photoconduction property of c-Se microwire with high quality and longer continuous length makes it possible to apply to functional devices and arrays.