Tm^(3+)-doped tellurite glass with Yb^(3+) energy sensitized for broadband amplifier at 1400–1700 nm bands

A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.

Spectroscopic Properties of Nd^(3+)-Doped Tellurite Glasses

The Nd^3＋-doped pared. The absorption and tellurite glasses were preemission spectra of Nd^3 ＋- doped tellurite glasses at room temperature were measured. The Judd-Ofelt parameters （Ω2, Ω4, Ω6） of the glasses were calculated from measured absorption spectra. The calculation results of luminescence properties （A, β, τrad, σ） of Nd^3＋ ions in the tellurite were glasses were given. Spectroscopic properties, concentration quenching in these kinds of the glasses were investigated. The results indicate that the tellurite glasses with composition of 70% TeO2, 20% ZnO, （ 10 - x ） % La2O3, x % Nd2O3 （ mol% ） show high emission cross section and low phonon energy. The fluorescent intensity and the emission cross section have a maxi- mum value at x = 0.5, namely, the optimum Nd^3 ＋ ion concentration in the tellurite glass is 0.5% （1.93 × 10^20 ions·cm^-3）. The fluorescence properties of Nd^3＋ measured are basically in accord with the calculated results.

Upconversion properties of Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glasses

The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3＋/Er^3＋ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3＋/Er^3＋ is also studied, The luminescence intensity increases with the ratio of Yb^3＋/Er^3＋ increasing. The ratio of Yb^3＋/Er^3＋ plays a more important role than the concentration of Er^3＋ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3＋/Er^3＋ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers.

Spectroscopic Properties of Er~ (3+), Yb^(3+)-Codoped Tellurite Glass-Ceramics Containing Nanocrystals

A transparent tellufite glass-ceramic containing nanocrystals based on the composition of 15Li2O-15Nb2O5-7OTeO2-0. 1ErEr2O3-0. 4Yb2O3 （mol%）was prepared by using a two-step heat-treatment. The XRD patterns show that the composition of crystals in glass-ceramics is possibly Yb6Te5O19.2 or Er6Te5O19.2, and the dimension of crystals is about 55 nm. The Judd-Ofeh parameters, Ωt, （t = 2, 4, 6）, and the spontaneous emission probability of Er^3＋ in glass and glass-ceramics were calculated from optical absorption spectra. The absorption cross section of Er^3 ：^4I15/2→I13/2 and the emission cross section of Er^3 ＋ ：^4I15/2→I13/2 in two samples were also calculated. Raman scattering spectra of glass and glass-ceramic were measured, the fluorescence spectra and the upconversion spectra of Er^3 ＋ ion in glass and glass-ceramic were compared.

Spectroscopic Properties of Er^(3+)-Doped TeO_2-WO_3-ZnO-ZnF_2 Glasses

The Er^(3+)-doped TeO_2-WO_3-ZnO-ZnF_2(TWZOF) glasses were prepared. The absorption spectra, 1.5 μm emission spectra and fluorescence lifetimes of Er^(3+), excited at 970 nm, were measured. The J-O parameters Ω_ t (t =2, 4, 6), absorption and emission cross-sections were calculated. The dependence of the 1.5 μm emission intensity, fluorescence lifetime and bandwidth of the Er^(3+) emission upon the contents of ZnF_2 in glass were investigated. In TWZOF glass, Er^(3+) ions had a broad emission profile around 1.5 μm with the maximum FWHM of 83 nm. With the increasing of the content of ZnF_2, the emission intensity at peak wavelength and the fluorescence lifetime of Er^(3+) at 1.5 μm increase.

Infrared-to-green upconversion properties of Er^(3+)/Yb^(3+) co-doped TeO_2-TiO_2-K_2O glasses upon excitation with 976 nm lasers diode

The energy transfer and upconversion of Er 3+ /Yb 3+ co-doped TeO2-TiO2-K2O glasses upon excitation with 976nm lasers diode were studied. The tellurite glasses were prepared by conventional melting methods. Their optical properties and sensitization upconversion spectra were performed. The dependence of green upconversion luminescence intensity on the mole ratio of Yb 3+ to Er 3+ and Er 3+ concentration were discussed in detail. When the mole ratio of Yb 3+ to Er 3+ is 25/1 and Er 3+ concentration is 0.1% （mole fraction）, or when the mole ratio of Yb 3+ to Er 3+ is 10/1 and Er 3+ concentration is 0.15%, the optimal upconversion luminescence intensity is obtained. The obtained glasses can be one of the potential candidates for lasers-diode pumping microchip solid-state lasers.

The influence of cation additives on the NIR luminescence intensity of Er~(3+)-doped borate glasses

Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency.

Preparation and ASE Spectrum of a Single-Mode Erbium Doped Tellurite Glass Fiber with D-type Cladding Geometry

Based on the host of tellurite glasses, the glass formation, preform manufacture, and fiber fabrication are described. The characterization of amplified spontaneous emission (ASE) from this newly fabricated single-mode Er3+-doped tellurite fibers is also presented. When pumped at 980 nm, a very broad erbium ASE around 1.53 μm was observed. The variations of ASE with fiber length and pumping power are measured and discussed. The output of 2 mW from Er3+-doped tellurite fiber ASE source was obtained under the pump power of 660 mW.

Improved Fluorescence from Tm^3＋/Er^3＋/Ce^3＋ Triply Doped Bismuth-Silicate Glasses for S＋C-bands Amplifiers

Fluorescence of Tm^3＋/Er^3＋ codoped bismuth-silica （BS） glasses and the sensitization of Ce^3＋ are investigated, It shows that Ce^3＋ codoping with Tm^3＋/Er^3＋ in BS glasses results in a quenching of Tm^3＋ ion emission from ^3F4 to the ^3H6 level. Consequently, the 1.47μm emission occurs after the population inversion between the ^3H4 and ^3F4 levels. Furthermore, the codoped glasses show the broad emission spectra over the whole S and C bands with full-width at half-maximum （FWHM） up to about 119nm, as it combines 1.55μm emission band of Er^3＋ with 1.47μm emission band of Tm^3＋ under 800hm excitation.

Effects of Yb^3＋ in Er^3＋/Yb^3＋ Codoped Fluorophosphate Glasses

For the Er^3＋ /Yb^3＋ codoped fluorophosphate glasses, Judd-Ofelt theory is used to analyse the influence of YbF3 as not a sensitizer but an average component on the spectroscopic properties around 1530nm emission. The double roles of Yb^3＋, as a sensitizer and as an average component, are discussed. It is found that Yb^3＋ as an average component contributes to the increase of fluorescence lifetime, and Yb^3＋ as a sensitizer has the best sensitization when its concentration is 2.4 mol%.

Er^(3+)/Yb^(3+)共掺TeO_2-Li_2O-B_2O_3-GeO_2玻璃系统的光谱性质和热稳定性研究

制备了Er3+ /Yb3+共掺的70TeO2 5Li2O (25 x)B2O3 xGeO2 (x=0, 5, 10, 15, 20mol% )系列玻璃,研究了玻璃的热稳定性能,测试了玻璃的吸收光谱、荧光光谱以及Er3+离子4I13 /2能级荧光寿命,并根据McCumber理论计算了Er3+离子4I13 /2→4I15 /2跃迁的受激发射截面 结果表明:随着GeO2 含量的增加,玻璃的热稳定性逐渐提高,荧光谱线半高宽(FWHM)保持在70nm左右,而荧光强度和Er3+离子4I13 /2能级荧光寿命逐渐提高,研究表明这种玻璃系统是一种具有应用潜能的宽带光纤放大器用的基质材料。

含纳米晶颗粒的Yb^(3+)/Er^(3+)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Er3+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Er3+∶4I15/2→4I13/2跃迁自发辐射几率,根据Mc-Cumber理论计算了Er3+∶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1.5μm处荧光和上转换光谱特性。

Er^(3+)/Tm^(3+)共掺碲酸盐玻璃光谱特性及能量传递

采用高温熔融法制备了两系列不同掺杂比的Er3+/Tm3+共掺的碲酸盐玻璃,测试了样品的吸收光谱和在980nmLD激发下的发光光谱、上转换发光光谱及发光寿命。讨论了Er3+与Tm3+掺杂浓度对样品光谱性质的影响,Tm3+离子的掺入会减弱Er3+的1.53μm发光强度,但通过共振能量传递可以获得Tm3+的1.8μm发光,并随着Tm3+离子浓度的增加而增强。同时表明Tm3+离子的增加会减弱Er3+离子在528nm和545nm附近的上转换绿光强度,而上转换红光出现了先增强后减弱的现象。研究了Er3+/Tm3+共掺杂碲酸盐玻璃的能量传递机制与传递效率,分析了Tm3+/Er3+离子掺杂浓度比对上转换发光的影响。

Yb^(3+)/Er^(3+)共掺杂TeO_2-WO_3-ZnO玻璃的光谱性质

制备了Yb3+/Er3+共掺杂的TeO2 WO3 ZnO玻璃,测量了Er3+在玻璃中的吸收光谱和970nmLD激发下的荧光光谱、荧光寿命和上转换光谱。计算了Yb3+/Er3+间的能量传递效率和Er3+离子1.5μm波段的吸收截面、发射截面,并研究了其荧光强度和上转换发光与Yb3+掺杂浓度间的关系。结果表明,Yb3+共掺杂可明显提高Er3+离子1.5μm发射的荧光强度,实验所得Yb3+离子的最佳掺杂浓度为Er3+离子浓度的3倍,在7.28×1020ions/cm3左右。Er3+离子1.5μm发射的荧光半峰全宽为67～72nm;上转换红、绿光均为双光子过程,随Yb3+掺杂浓度的增加,上转换红、绿光强度均增强。

Er^(3+)/Yb^(3+)共掺碲钨酸盐玻璃的热稳定性和1.5μm波段的光谱性质(英文)

制备了Er3 +/Yb3 +共掺的碲钨酸盐玻璃样品,TeO2-WO3-RmOn(RmOn=PbO,BaO,La2O3,Bi2O3),研究了样品的热稳定性和1.5μm波段的光谱性质。碲酸盐中引入WO3的目的是为提高基质的声子能量,使Er3 +离子4I13/2→4I15/2的多声子弛豫速率增加,从而提高4I13/2能级上的Er3 +离子数,这对提高1.5μm处的荧光强度有利,另外加入WO3也能提高碲酸盐玻璃的抗析晶能力。测试了样品的FT-IR光谱,发现碲钨酸盐玻璃样品中存在着TeO4、TeO3、WO4和WO6结构体。周围环境的不对称性导致Er3 +在1.5μm处的光谱有非均匀的展宽和大的受激发射截面。Er3 +在70TeO2-20WO3-10Bi2O3玻璃中4I13/2→4I15/2能级发射的荧光半峰全宽(FWHM)为77 nm,应用McCumber理论计算的受激发射截面(σpeak)为1.03×10-20cm2。其FWHM×σpeak乘积远大于掺Er3 +的铋酸盐、磷酸盐、碲酸盐和硅酸盐玻璃,说明碲钨酸盐玻璃是一种制备宽带光纤放大器优良基质材料。

铒离子浓度对掺Er^(3+)碲酸盐玻璃的Judd-Ofelt理论参数的影响

制备了四种不同铒离子掺杂浓度的碲酸盐玻璃,通过测定吸收光谱计算了吸收谱线的振子强度,根据Judd-Ofelt理论计算了不同浓度下Er3+离子发光光谱的强度参数Ωi(i=2,4,6),计算了自发辐射电偶和磁偶跃迁概率、辐射寿命、荧光分支比等参数,讨论了Er3+离子浓度变化对以上这些参数的影响。测试了Er3+4I13/2→4I15/2跃迁对应的荧光光谱和Er3+4I13/2能级荧光寿命。最后应用McCumber理论计算了玻璃中Er3+4I13/2→4I15/2跃迁对应的受激发射截面大小。结果表明振子强度基本上随Er3+离子浓度的增大而增强;随着Er3+离子浓度的增加,自发辐射跃迁概率A基本呈现出递增的趋势,但荧光分支比β却只有很小的变化;Er3+4I13/2→4I15/2的发射截面随Er3+离子浓度的增大而改变很小,有效线宽都在50nm左右。

Er^(3+)离子掺杂的碲酸盐玻璃光谱性质分析

用976 nm光激发测量了室温下掺Er3+碲酸盐玻璃的上转换发光,讨论了上转换发光机制.同时测量了掺Er3+离子碲酸盐玻璃的吸收光谱和荧光光谱,发现掺Er3+离子碲酸盐玻璃的荧光半高宽可达80 nm,应用McCumber理论计算了1 531 nm处的受激发射截面可达0.75×10-20cm2.对Er3+离子在不同基质玻璃中光谱特性的比较,发现了Er3+离子在碲酸盐玻璃中具有相对较高的受激发射截面和宽的荧光半高宽.

平面光波导放大器用掺Er^3＋磷碲酸盐玻璃的研究

制备并研究了掺Er^3＋磷碲酸盐玻璃的热力学稳定性、吸收光谱、荧光光谱、Raman光谱和上转换发光性能。应用McCamaber理论计算了Er^3＋离子从能级^4I13／2到能级^4I15／2跃迁的受激发射截面并分析了掺Er^3＋磷碲酸盐玻璃带宽特性和上转换发光性能。结果表明由于五氧化二磷的加入碲酸盐玻璃的各项性能参数都有所变化，掺Er^3＋磷碲酸盐玻璃具有较高的热稳定性、较好的带宽特性，同时上转换发光得到了较好的抑制，这说明其是一种优良的宽带平面光波导放大器的潜在的基质材料。

一种Er^(3+)/Yb^(3+)共掺锗碲铋钾玻璃的光谱性质

用熔融法制备了Er3+/Yb3+共掺TeO2-GeO2-B i2O3-K2O玻璃样品,对玻璃进行了差热分析并测试了玻璃的吸收光谱和上转换光谱.应用Judd-Ofelt理论计算了Er3+/Yb3+共掺锗碲铋钾玻璃的3个强度参数,及Er3+各能级的振子强度、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数.通过977 nm的激光二极管抽运,在室温下同时观察到绿色(522和546 nm)和红色(658 nm)的荧光发射,分别是由于Er3+自2H11/2→4I15/24、S3/2→4I15/2和4F9/2→4I15/2跃迁而产生.强烈的绿光和红光发射均来源于双光子吸收过程.

掺Er^(3+)钨碲玻璃光纤放大器的特性研究

以WO3、TeO2、ZnO和Na2O为基质制备了掺Er3+钨碲(EDWTZn)玻璃.差热分析表明EDWTZn玻璃的转变温度达到427℃,比常规碲酸盐玻璃具有更高的热稳定性.McCumber原理研究的结果显示,EDWTZn玻璃在1530nm处的峰值受激发射截面和荧光发射半高宽分别为9.52×10-21cm2和86nm.数值模拟结果表明,EDWTZn光纤放大器利用较短的激活长度就可获得足够的信号光放大,在1530nm波长附近能提供极宽的平坦增益带,当输入信号光功率为0dBm时,在大约70nm带宽范围内的平均信号增益大于20dB,不平坦度小于5dB.