Finite-element analysis of single-frequency silica-based Er3+-Yb3+ co-doped waveguide lasers

Continuous wave laser operations of silica-based Er³⁺-Yb³⁺ co-doped waveguides have been numerically analyzed by means of a finite-element method. The theoretical model, based on propagation-rate equations, describes uniform upconversion by a dipole-dipole interaction between Er³⁺ ions, and includes a pair-induced energy transfer process from Yb ³⁺-Er³⁺ Numerical results show that single-frequency operation with slope efficiency higher than 50% and threshold pump powers of few mW can be achieved in short and heavily doped waveguides equipped with input dielectric mirrors and output distributed Bragg reflectors     

Optimum design of Er3+-Yb3+ codoped fibersfor large-signal high-pump-power applications

A comprehensive numerical fiber amplifier model has been used to optimize Er³⁺-Yb³⁺ codoped active fiber for maximum gain and quantum conversion efficiency (QCE) at large signal operation. The optimum cutoff wavelength of the LP₁₁ mode has been found to increase from 800 mm at low pump powers (≈50 mW) to 1400 mn at pump powers higher than 500 mW. While at low pump powers fibers with higher numerical aperture give higher QCE, at high pump levels better large signal performance is achieved with fibers having lower numerical aperture     

A simple set searching optimization method for Er3+-Yb3+ co-doped fiber lasers

A simple set searching optimization algorithm is proposed for Er³⁺-Yb³⁺ co-doped fiber lasers in this paper. This method enables fiber lasers to acquire the optimum fiber length and Yb³⁺-Er³⁺ concentration ratio for a given accuracy. The numerical results illustrate that the optimum Yb³⁺-Er³⁺ concentration ratio changes very little, the optimum fiber length shortens and the corresponding output power is increased with erbium ions concentration increasing. The total Yb³⁺ and Er³⁺ contents are nearly constant under certain pump power, while the optimum total erbium ions and ytterbium ions are decreased with pump power decreasing.     

Optical thermometry through infrared excited upconversionfluorescence emission in Er3+- and Er3+-Yb3+-doped chalcogenide glasses

Optical thermometry based upon infrared excited upconversion fluorescence emission in Er³⁺- and Er³⁺-Yb³⁺ - doped Ga₂S₃-La₂O₃ chalcogenide glasses excited at 1.54 and 1.06 μm, respectively, is presented. Temperature sensing in the region of 20°C-220°C with 0.3°C accuracy using excitation powers readily obtainable from commercially available semiconductor lasers was achieved. The temperature sensing approach is independent of fluctuations in excitation intensity and transmission and requires a simple and low-cost signal detection and processing system. The results also indicate that the glassy host material plays a major role in the performance of the sensing system     

Anomalous dispersion in Er3+ and Yb3+-dopedfibers

In experimental and theoretical study of anomalous dispersion in Er³⁺and Er³⁺-Yb³⁺-doped fibers has been developed. Anomalous time delay caused by both absorption and emission at 1.535 μm has been theoretically calculated and experimentally measured. A pump power dependence of anomalous time delay in rare-earth-doped fibers has been theoretically calculated and experimentally investigated. It has been shown that pump power fluctuations lead to propagation time jitter in Er³⁺-doped fiber amplifiers. The pulse interaction due to refractive index change caused by gain saturation is predicted. It has been shown that for Er ³⁺-doped fibers with SiO₂-GeO₂ core composition, the anomalous dispersion per 1-dB gain is twice that of fibers with SiO₂-Al₂O₃ core, which is caused by gain curve form difference. A scheme of mutual compensation of intrinsic fiber dispersion and anomalous dispersion caused by Er³⁺ in the region 1.532-1.537 μm has been suggested     

Er3+/Yb3+双掺光纤放大器理论模型

本文在分析一些文献的基础上,仿照掺Er3+光纤放大器的理论模型,尝试建立了一个Er3+/Yb3+双掺光纤放大器的理论模型。利用本模型,可以模拟双掺光纤中信号、泵浦及放大的自发辐射(ASE)的变化情形,并得到一些有意义的数值结果。     

Diode-array pumping of Er3+/Yb3+ Co-dopedfiber lasers and amplifiers

Single-mode double-clad Er³⁺/Yb³⁺ co-doped fibers are shown to be suitable for diode array pumping at around 960 nm. A fiber laser with 96-W output power at 1.53 μm and a power amplifier exhibiting a small signal gain of 24 dB and a saturated output power of +17 dBm are reported     

Er3+:YAlO3 upconversion laser

Upconversion lasing in Er:YAlO₃ is reported. Laser emission was produced using both sequential two-step pumping and cross-relaxation energy transfer. In addition, photon avalanche upconversion pumping was demonstrated. Selection among these pumping mechanisms is determined by the pump wavelength, and laser operation was obtained with excitation between 785 nm and 840 nm. The highest laser output power was achieved at 34°K, where 918 mW of pump power at 807 nm produced 121 mW of TEM₀₀ emission. The optical conversion efficiency was 13%. Repetitively Q-switched operation is reported, and the temporal- and temperature-dependence of the laser output is discussed     

掺饵氟化物玻璃光谱和上转换发光的研究

研究了掺铒氟锆酸盐玻璃的光谱和可见光区的发光性质，及其与玻璃中氯含量的关系。结果表明玻璃中阴离子组成对发光性质具有更大的影响。用８００ｎｍ钛宝石激光作光泵源，测定了块状玻璃和光纤的上转换发光。在所有样品中都观察到由跃迁产生的．中心波长在５５０ｎｍ附近很强的发光。研究了影响上转换发光的诸因素。     

LD泵浦Er3+: Yb3+共掺全固态激光器设计

对LD泵浦Er3+:Yb3+共掺全固态激光器进行了整体设计,利用矩阵光学方法推导了高斯光束经耦合系统聚焦后束腰宽度和像距的计算公式。考虑激光棒的热透镜效应,对有源平平腔、平凹腔进行了数值计算,分析了谐振腔的稳定性。最后,根据激光谐振条件,确定了激光输出镜及滤光片的镀膜方案,为最终获得高效率、稳定的激光输出提供了理论依据。     

Laser action from Ho3+, Er3+, and Tm3+in YAlO3

Laser action has been observed for the following rare-earth ions in YAlO3:Ho³⁺(sensitized with Er³⁺and Tm³⁺), Er³⁺, and Tm³⁺(sensitized with Er³⁺) at wavelengths of 2.123, 0.851, and 1.861 μm, respectively. Measurements of spectroscopic properties, fluorescence kinetics, and laser performance of these ions in YAlO3are reported.     

磷酸盐玻璃中稀土离子Ce~(3 )、Tb~(3 )、Er~(3 )和Tm~(3 )的能量转移和敏化过程的研究

本文报道了磷酸盐玻璃中Tb~(3 )和Ce~(3 )的浓度猝灭效应。在KrF激光(248毫微米,10毫微秒)激发下,测出磷酸盐玻璃中不同浓度Ce~(3 )或Tb~(3 )离子的荧光寿命。着重讨论了磷酸盐玻璃中Ce~(3 )→Tb~(3 )、Er~(3 )和Tm~(3 )的能量转移和敏化过程。     

YP_5O_(14):Er~(3+),Tm~(3+)晶体的合成

研究了水热法合成晶体,浓度配比、生长温度对晶体生长习性的影响.合成了一系列化学计量比的Y_(1-x-0.3)Er_(0.3)Tm_xP_5O_(14)(x=0.01～0.1)晶体,观察和分析了晶体的缺陷及成因,测定和讨论了晶体结构.     

Infrared cross-section measurements for crystals doped withEr3+, Tm3+, and Ho3+

The absorption and emission cross sections of the transition between the ground spin-orbit multiplet and the lowest excited multiplet were measured for Er³⁺, Tm³⁺, and Ho³⁺ ions in a variety of crystalline hosts. The materials that were investigated include LiYF₄, BaY₂F₈, Y ₃Al₅O₁₂, LaF₃, KCaF₃ , YAlO₃, and La₂Be₂O₅. The absolute magnitudes of the emission cross sections were determined from the absorption spectra, with the aid of the principle of reciprocity. The calculated radiative emission lifetimes derived from these measured cross sections agree well with the measured emission decay times for most materials. The potential use of these rare-earth-doped materials in pulsed laser applications requires that the ground state exhibit adequate splitting to minimize the detrimental effects of the ground state thermal population, and also that the emission cross section be sufficiently large to permit efficient extraction energy. The systems based on Ho³⁺ in the eightfold coordinated sites of LiYF₄, BaY₂F₈, and Y₃Al₅O₁₂ appear to be the most promising     

双包层Er3+/Yb3+共掺光纤放大器动态特性研究

基于速率方程的离散算法,实现了对双包层Er3+/Yb3+光纤放大器动态特性的分析.研究了不同信号和泵浦功率下单信道的瞬态功率、脉冲序列输出功率与增益随时间的变化以及多信道异步转移模式下输出功率和增益随时间的变化.结果表明对于单个脉冲,在相同的泵浦功率下,输出脉冲的峰值功率取决于输入脉冲的峰值功率;在不同的泵浦功率下,输出脉冲的峰值功率取决于泵浦功率.对于脉冲序列,在达到稳定的输出前,将经历一个输出功率和增益由高到低的变化过程.对于异步转移模式的多信道脉冲,脉冲重叠时的功率和增益变化要快于非重叠时功率和增益的变化.     

Er^3＋／Ce^3＋共掺碲铌酸盐玻璃的制备及光学特性研究

采用高温熔融退火法制备了系列75TeO2—10Nb2O5-10ZnO-5Na2O-0．5Er2O3-xCe2O3=（x=0．00,0．25,0．50,0．75,1．00mol％）和（75-y）TeO2-10Nb2O5-10ZnO～5Na2O～yB2O3—0．5Er2O3-0．75Ce2O3（y=2,5,10,15mol...     

Fluorescence dynamics of Er3+ and Ho3+ ionsand energy transfer in some fluoride glasses

A detailed study at room temperature of the fluorescence dynamics of Er³⁺ and Ho³⁺ ions and energy transfer processes Er³⁺→Ho³⁺ in the ABLA, BATY, and BIZYT fluoride glasses is reported. Numerous concentrations and different selective laser excitations in the visible and infrared spectral ranges are used. The best concentrations and the more suitable glasses for laser applications at 2 μm are determined     

Er3+、Eu3+双掺杂LaOF荧光粉的光学性能研究及防伪应用

有机发光材料可能对人体或环境造成影响,除此之外还有生产成本高、发光易淬灭、发光强度与颜色不易于控制的缺点,因此探索性能优越的稀土发光材料并寻找其应用价值是具有重要意义的。本文基于水热辅助固相法制备出Er³⁺、Eu³⁺离子共掺杂LaOF荧光粉,通过X射线衍射仪(X-ray diffractometer, XRD)、扫描电镜(scanning electron microscope, SEM)和荧光分析仪对不同Er³⁺掺杂浓度下的LaOF∶Eu³⁺荧光粉体的相组成、粒径尺寸、形貌及荧光光谱进行表征与分析。结果表明：在900℃的温度下煅烧,物相由前驱体LaF₃转变为四方相LaOF,且随着Er³⁺掺杂浓度的升高,在365 nm与393 nm波长激发下均呈现出多色可调谐的发光特性,其中365 nm激发下呈现自橙色光向黄色光的转变,而在393 nm光辐射下则由橙色光向品红色光过渡。将Er³⁺、Eu³⁺共掺杂LaOF荧光粉制成...     

多波长Er3+:YAlO3激光的偏振特性

本文从实验上研究了掺杂10at%Er3+离子a轴Er3+YAlO3（Er:YAP）激光器同时起振的2.7110μm,2.7299μm和2.7950μm三条谱线的偏振特性,发现2.7110μm和2.7950μm激光为线偏振光,其偏振方向平行结晶的b轴方向.2.7299μm激光为部分偏振光,椭圆的长轴沿结晶的c轴方向.文中给出了三者的输出特性.