Novel Bi-doped glasses for broadband optical amplification

Broadband infrared luminescence is observed in various Bi-doped oxide glasses prepared by conventional melting-quenching technique. The absorption spectrum of the Bi-doped germanium oxide glass consists of five broad peaks at below 370, 500, 700, 800 and 1000 nm. The fluorescence spectrum exhibits a broad peak at about 1300 nm with full width at half maximum (FWHM) of more than 300 nm when excited by an 808 nm laser diode. The fluorescence lifetime at room temperature decreases with increasing Bi2O3 concentration. Influence of the glass composition and melting atmosphere on the fluorescence lifetime and luminescent intensity is investigated. The mechanism of the broadband infrared luminescence is suggested. The product of stimulated emission cross-section and lifetime of the Bi-doped aluminophosphate glass is about 5.0 X 10(-24) cm(2) s. The glasses might be promising for applications in broadband optical fiber amplifiers and tunable lasers. (c) 2007 Elsevier B.V. All rights reserved.

碱金属和碱土金属氟化物对掺Er^3＋氟磷酸盐玻璃光谱性质的影响

研究了碱金属和碱土金属离子修饰的掺Er^3＋氟磷酸盐玻璃的光谱性质，讨论了碱金属和碱土金属对铒氟磷玻璃的吸收和发射截面、荧光半高宽，Judd-Ofelt强度参数和上转换发光强度等光谱性质的影响，并与一些传统氧化物玻璃系统进行了比较．研究表明碱金属K^＋和碱土金属Sr^2＋掺杂高的玻璃更适宜用作光放大器基质．含12mol％K^＋的氟磷玻璃展现出7．83×10^-21cm^2的高发射截面和最小的荧光上转换强度；含23mol％Sr^2＋的氟磷玻璃则有7．58×10^-21cm^2的高发射截面、65nm的荧光半高

Yb3+-doped 200 mu m diameter core, gain guided index-antiguided fiber

The lasing in an end-pumped gain guided index-antiguided (GG-IAG) Yb3+-doped silicate glass fiber with a 200 mu m diameter core is demonstrated. Laser beams with similar beam propagation factors M (2) and mode field diameters W (0) (> 160 mu m) were observed at the output end of the GG-IAG fibers under different pump powers, which indicated that single mode behavior and excellent beam quality were achieved during propagation. Furthermore, the laser amplifier characteristics in the present Yb3+-doped GG-IAG fiber were also evaluated.

Preparation and characterization of erbium doped sol-gel silica glasses

Erbium-doped silica glasses were made by sol-gel process. Intensive photoluminescence (PL) spectra from the Er-doped silica glasses at room temperature were measured. A broadband peak at 1535 ma, corresponding to the I-4(13/2)-I-4(15/2) transition, its full width at half-maximum (FWHM) of 10 nm, and a shoulder at 1546 nm in the PL spectra were observed. At lower temperatures, main line of 1535 nm and another line of 1552 Mn instead of 1546 nm appear. So two types of luminescence centers must exist in the samples at different temperature. The intensity of main line does not decrease obviously with increasing temperature. By varying the Er ion concentration in the range of 0.2 wt% - 5wt%, the highest photoluminescence intensity was obtained at 0.2wt% erbium doped concentration. Luminescence intensity decreases with increasing erbium concentration. Cooperative upconversion was used to explain the concentration quenching of luminescence from silica glass with high erbium concentration. Extended X-ray absorption fine structure measurements were carried out. It was found that the majority of the erbium impurities in the glasses have a local structure of eight first neighbor oxygen atoms at a mean distance of 0.255 nm, which is consistent with the typical coordination structure of rare earth ion.

高功率光子晶体光纤激光器研究进展

光子晶体光纤的出现，为高功率光纤激光器的关键技术-大模区光纤的实现提供了新途径。基于铒镱共掺磷酸盐材料的包层掺杂新结构出现，为实现更加紧凑的光纤激光器提供了可能。常规高功率光纤激光器中的抽运技术，谐振腔技术和相干组束技术也在不断融入高功率光子晶体光纤激光器。高功率光子晶体光纤激光器的调Q和锁模输出也已经实现。

两微米瓦级掺铥短光纤激光器

以短的高掺杂浓度的掺铥硅基光纤为增益介质，采用790 nm波长的激光二极管(LD)为抽运源，得到了波长为2 μm的高功率激光输出。当光纤长度为7 cm时，激光器的阈值泵浦功率为135 mW，最大输出功率为1.09 W，斜率效率为9.6%(相对于耦合进光纤的抽运功率)。该激光器的输出稳定性在5%以内。此外，我们还观察分析了工作温度和其他腔结构参量对该激光器工作性能的影响。

Yb：铅锌镧碲酸盐玻璃的热学、光谱和激光性质

研究了摩尔组分为70TeO2-(20-x)ZnO-xPbO-5La2O3-2.5K2O-2．5Na2O(x=0，5，10，15，20)的新型多元铅锌镧碲酸盐激光玻璃，外掺Yb2O3为玻璃摩尔组分的1％，测试了试样的物理性质及吸收光谱、荧光光谱和荧光寿命，计算了Yb^3+的吸收截面、受激发射截面、荧光有效线宽等光谱参数，结果表明：该系列玻璃都具有良好的热学稳定性((Tx-Tg)>195℃，高于TZN玻璃(118℃))；当X=15时，样品具有较好的光谱性质：高的受激发射截面(1．25pm^2)、长的荧光寿命(

频率上转换掺稀土氧氟纳米微晶玻璃的研究进展

本文综述了近年来用于上转换发光的掺稀土离子氧氟微晶玻璃的研究概况，系统阐述了氧氟微晶玻璃中的上转换发光特性及其机理，提出了值得进一步研究的工作并对掺稀土离子氧氟微晶玻璃未来的前景做出了展望。

具有高机械强度的掺Er^3＋：TeO2-Nb2O5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σcmi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．

掺Er^3＋碲酸盐玻璃热稳定性的改进

制备了掺Er^3+-TeO2-ZnO-Na2O-Nb2O5和TeO2-PbO-B2O3系统玻璃，测定了玻璃的热稳定性和吸收光谱，在碲-锌-钠多组分玻璃中具有不同的玻璃转变温度Tg和开始析晶温度Tx，按照Hruby’s参数HR=(Tx-Tg)／(T1-Tc)；(Tx-Tg)越大则玻璃稳定性越好，在TeO2-ZnO-Na2O系统玻璃中ZnO含量增加则(Tx-Tg)增大，加入少量(小于10％(摩尔分数))Nb2O5，PbO使(Tx-Tg)变大，玻璃的热稳定性变好。

杂质对掺钕磷酸盐激光玻璃光谱性质的影响

综述了过渡金属杂质（Cu，Fe）和稀土杂质（Dy，Pr，Sm，Ce）对掺钕磷酸盐激光玻璃吸收损耗及Nd^3＋荧光猝灭影响的研究状况。

铬镱铒共掺磷酸盐玻璃光谱和激光性质研究

测定了Cr14—05铬镱铒共掺磷酸盐玻璃的主要热光参数，并测试了吸收、荧光光谱和激光性能等。结果表明该玻璃具有较好的光谱和热光性质，其激光输出性能可满足人眼安全激光测距光源应用的要求。

Al2O3,B2O3对磷酸盐包边玻璃形成区和物化性质影响研究

研究了Al2O3 ,B2O3对P2O5-Al2O3-B2O3-ZnO-Na2O-CuCl玻璃形成区的影响规律；包边玻璃的物化性质随B/(B+Al)的变化规律；以及特定组分包边玻璃的透射光谱和吸收系数。这些研究工作对高功率大尺寸钕磷酸盐激光包边玻璃的研制具有非常重要的意义。

钕离子掺杂和钕铝共掺高硅氧玻璃的光谱性质研究

Nd-doped and Nd-Al-codoped high silica glasses were obtained by sintering porous glass impregnated with Nd3+ and Al3+ ions. The absorption, fluorescence spectra and fluorescence lifetime of Nd-doped and Nd-Al-codoped high silica glasses were measured. The intensity parameters Omega(1), ( t = 2, 4, 6), fluorescence lifetime, radiative quantum efficiency and stimulated emission cross section were calculated by Judd-Ofelt theory. The effect of aluminum codoping on the fluorescence and structural properties of Nd-doped silica glass has been discussed. By comparing the spectroscopic properties with other Nd-doped oxide glasses and commercial silicate glasses, this Nd-doped high silica glass is likely to be a promising laser material for use in high power and high repetition rate lasers.

不同玻璃组分对掺铒碲酸盐玻璃 光谱性质的影响

Series of tellurite glasses were prepared by traditional melting method, the glass composition were changed and the different effects of glass modifier oxides(alkali metals and alkaline earth metal oxides) and glass intermediate (Y2O3, GeO2, Nb2O5, WO3) on the optical and spectroscopic properties of Er³⁺ doped tellurite glass were researched and compared. The infrared transmitting spectra, absorption spectra and fluorescence spectra were tested, the results showed that Nb2O5 and WO3 in the glass act as part of the body's role in the formation of the network, caused the reduction of transmitting range in infrared wavelength, which decrease the transmitting properties of tellurite glass. The introduction of high valence cationic ions, WO3 especially, can increase the FWHM of Er³⁺ for the increased polarization effect. With the decreasing of cationic field of glass modifier ions, the ion filed of the environment around Er³⁺ increased, subsequently, the role of ligand field polarization effect reduced, which makes the luminescence lifetime increase, and on the contrary the FWHM decrease monotonously.