LD泵浦的掺Nd双包层光纤激光器

本文对LD泵浦掺Nd双包层光纤激光器进行了实验研究.在现有的泵浦功率下,得到了超过1.2W 的连续激光输出,斜率效率为18.6％,并对光纤激光器的光谱特性和时域特性进行了初步的分析.     

Yb3+-doped large-mode-area photonic crystal fiber laser with 210 W continuous-wave output power

An Yb^3＋-doped double-clad large-mode-area photonic crystal fiber （LMA PCF） laser with up to 210 W of continuous-wave output power centered at 1.05 lira is demonstrated. The length of the fiber used is 2 m and the produced laser power per meter can attain 105 W. The PCF is pumped by two diode lasers with central wavelength of 976 nm. The slope efficiency is 76%, and the beam quality factor M^2 at x and y axes are measured to be 1.06 and 1.08, respectively. No thermo-optical problems and other roll-over even are observed at the highest output power.     

以双包层光纤光栅为后腔镜的掺Yb3+双包层光纤激光器的研究

本文对LD泵浦以双包层光纤光栅为后腔镜的掺Yb3 双包层光纤(DCF)激光器进行了实验研究．采用相位掩模法直接在内包层为圆形的掺Yb3 双包光纤一端写制反射率约为0．2 dB的光栅,并用其作后腔镜, 以二向色镜为前腔镜构成了双包层光纤激光器．在1 054．6 nm处得到峰值半宽(FWHM)<0．1 nm的稳定单模激光输出,并对试验结果进行了理论分析．     

国产LD泵浦的掺镱双包层光纤激光器

本介绍了一种国产LD泵浦的高功率掺YB^3 双包层光纤激光器，泵浦功率2．15W时，得到了54W的功率输出，斜率效率达到86．1％．并对光纤激光器的光谱特性、时域特性进行了初步的研究和分析．     

双包层As2Se3硫化物光子晶体光纤受激布里渊散射慢光

研究了双包层As₂Se₃硫化物光子晶体光纤内、外包层结构对受激布里渊散射慢光特性的影响.在分析双包层As₂Se₃硫化物光子晶体光纤结构对布里渊增益谱的影响时,考虑了声场的高阶模式.研究结果表明,内包层占空比的变化对慢光特性影响较大,随内包层占空比的增加,布里渊增益谱的主峰逐渐降低,第二个峰值逐渐上升,时间延迟量增加,布里渊增益的变化趋势与其相似.但这些特性受外包层占空比的变化影响较小,布里渊增益谱的第二个峰值略微上升,而时间延迟及增益变化很小.因此双包层As₂Se₃硫化物光子晶体光纤的慢光特性受内包层占空比影响较大.而与内包层相比,这些特性受外包层占空比的影响较小.     

Er3+/Yb3+共掺双包层光纤放大器的增益特性

基于速率方程和功率传输方程,分析了Er³⁺/Yb³⁺共掺双包层光纤放大器增益特性随光纤长度的变化及信号光、抽运光功率对放大器增益的影响,并进行了实验验证。结果表明:有源光纤长度对放大器增益有影响,大信号输入时放大器达到增益饱和对应的光纤长度更短;放大器增益随着信号光和抽运光功率不同而变化,要适当调整其大小以获得较高的放大增益。     

双包层Er^3＋／Yb^3＋共掺光纤放大器系统结构设计及其性能分析

基于光传输方程,数值分析了所设计的双包层Er^3＋／Yb^3＋共掺光纤放大器系统结构在980nm泵浦下,输出信号功率和噪声特性;讨论了它们随输入信号功率、输入信号波长、泵浦信号波长和光纤包层面积的关系。结果表明,该系统结构在输入信号小于-30dBm,激活光纤长度为4m时,输出信号功率超过10dBm,增益高于35dB,噪声系数受光纤内包层与纤芯面积之比影响较大,且小于3．5dB．     

Neodymium cations Nd3+ were transported to the interior of Euglena gracilis 277

Euglena gracilis 277, a unicellular green alga, demonstrated remarkable ability to transport Nd³⁺ to the cell compartments. For a given amount of Nd³⁺ and cells, the results of ICP-AES indicated that the cellular uptake of Nd³⁺ was independent of Nd³⁺ concentration in the bulk solution. The average uptake of Nd³⁺ per cell (m _Nd) is proportional to a parameter ξ — the ratio of neodymium content to the cell counts of the system. A novel approach for probing cellular neodymium by tetraiodotetra chlorofluorescein (I4TCF) has been devised. Data derived from the cryosections of I4TCF-Nd³⁺ stained cells and EDAX of the fast freezing ultrathin cryosections indicate that Nd³⁺ is distributed over the cell compartments. Chloroplasts are the major compartments as the residence of Nd³⁺ in the alga. The transport should be against a concentration gradient of Nd³⁺ on the order of five, even higher. It is proposed that a calcium ion channel would play an important role in the Nd³⁺ transportation.     

球墨铸铁表面连续激光沉积高速钢粉末涂层的工艺与组织性能

采用大功率连续CO2激光器对预置了高速钢粉末的球墨铸铁基体进行激光辅助金属沉积处理.得到了激光沉积的优化工艺参数,用该参数制备的沉积层组织致密、无气孔、无裂纹等缺陷,沉积层与基体为冶金结合.XRD分析表明,Ni60+T15+T15沉积层中V4C3,WC1-x,CoCx等硬质相起到弥散强化的作用,Ni60+T15+T15沉积层平均硬度值为716HV,是基体的2.2倍.Ni60+YT12+YT12沉积层中起强化作用的Cr7C3相主要分布在晶界间,Ni60+YT12+YT12沉积层平均硬度值为739HV,约为基体的2.3倍.     

掺镱光纤激光器时域特性的研究

利用光纤的非线性效应－受激布里渊散射（SBS）和二色镜的选频利用,以国产的激光二极管作泵浦源,在掺镱光纤激光器中得到了稳定的自调Q光脉冲输出,脉冲重复频率为29．4MHz,脉冲光宽度约为2ns。     

Upconversion luminescence properties of Mn2+-doped NaYF4:Yb/Er nanoparticles

NaYF₄:Yb/Er upconversion nanoparticles doped with Mn²⁺ were synthesized by hydrothermal method. The upconversion photoluminescence measured by 975 nm continuous wave laser indicates that the as-synthesized samples generated green and red color emission with various intensity ratio ranging from 3.25 to 548.35, which is highly correlative to the dopant concentration of Mn²⁺. However, there is no red emission enhancement observed in Cu²⁺-doped NaYF₄:Yb/Er nanoparticles.     

结晶器铜板上激光熔覆镍基合金

利用5kWCO2激光器在结晶器铜板上熔覆镍基合金,并研究了熔覆层组织性能.选用与结晶器铜板成分相近的镍基自熔合金粉末Nickel-baseHMSP1015-00(Ni1015),利用等离子喷涂技术在铜板上预涂Ni1015合金,然后再采用高能量密度激光进行重熔.借助OM,SEM和显微硬度计分析测定了涂层的显微组织形貌、组织成分和截面显微硬度分布情况.所得到的熔覆层表面平整均匀,与基体为冶金结合;熔覆层平均显微硬度为270HV0.05,是基体的3.2倍(85HV0.05).确定出本实验合适的激光熔覆工艺参数功率密度为1.58×102kW/cm2时,扫描速度为3~4m/min.     

掺Nd^3＋光纤环形激光器及其对激光陀螺的可能应用

报道用Ar~ 激光泵浦抛磨型掺Nd~(3 )光纤定向耦合器构成的环形腔、环形激光器的激光阀值、双端输出功率、光谱、偏振等光学特性,并讨论其对激光陀螺应用的可能性。     

双包层Er3+/Yb3+共掺光纤放大器增益和噪声特性分析

基于速率方程和光传输方程，对980nm激光泵浦Er^3 ／Yb^3 共掺双包层光纤放大器的增益和噪声特性进行了分析。数值模拟结果表明，在小信号和大信号情况下，双包层Er^3 ／Yb^3 共掺光纤放大器在1520nm～1570nm波长范围内都具有良好的增益和噪声特性。     

碳钢表面激光涂敷硬质合金材料的性能分析

利用大功率CO2激光器在20#钢表面涂敷WC-B4C-SiC-Co,WC-SiC-Co,用X射线衍射仅对涂敷层进行物相分析,并对涂敷层的硬度及耐磨性能进行测试.结果表明,利用大功率激光束可在碳钢表面涂敷高硬度合金,提高了金属材料表面的硬度及耐磨性能[1,2,3].     

新型全光纤结构高功率双包层光纤激光器

通过对高功率双包层光纤激光器工作原理及其输出特性的分析,利用半导体激光器光纤模块作为泵浦源,采用星型双包层掺镱光纤与光纤光栅连接制作出全光纤结构的光纤激光器,获得了6.02 W单模连续输出功率,中心波长1 100 nm,斜效率1.7 W/A。     

Effects of the rare earth ions on bone resorbing function of rabbit mature osteoclasts<Emphasis Type="Italic">in vitro</Emphasis>

The osteoclast plays initiating and vanguard roles in the course of bone remodeling. The resorption and formation of bone is the basic clues of bone remodeling, which results from the mutual dependent functions of osteoclasts and osteoblasts. When the osteoclasts are activated, the bone resorption function is increased. The excess bone resorption leads to osteoporosis, characterized by formation of many hollows, lacunae and tunnels on the bone surface or in depth[1,2]. The differentiation, pro…     

Laser cooling using anti-stokes fluorescence in Yb3+-doped fluorozirconate glasses

The fluorozirconate glasses ZBLANP (ZrF₄−BaF₂−LaF₃−NaF−PbF₂) doped with different Yb³⁺ concentration were prepared. The Raman spectra and absorption spectra are measured to substantiate the existence of phonon-assisted emission. After analyzing the normalized absorption spectra of samples with different Yb³⁺-doped concentration, we calculated the maximum cooling effect in the 3 wt% Yb³⁺-doped sample pumped at 1 012.5 nm. The corresponding cooling capability is about −4.09 °C/W and the cooling efficiency reaches 1.76%. Foundation item: Supported by the Key Science Foundation of Wuhan (9601P0223) Biography: Xu Tian-ming (1978-), female, Master candidate, research direction: information optics and nonlinear optics.     

高功率F-P腔掺Yb双包层光纤激光器的性能及效率

对高功率法布里-泊罗腔(F—P)掺Yb双包层光纤激光器进行理论和实验研究．通过推导光纤激光器速率方程，得到了光纤激光器输出功率、斜率效率和阈值泵浦功率的解析表达式．重点讨论了F-P腔腔镜反射率对光纤激光输出的影响．在实验中，利用D型双包层掺Yb光纤获得了输出功率10．6W，斜率效率86％的连续激光输出．理论分析与实验结果一致．     

掺镱（Yb3＋）双包层光纤激光器实验研究

光纤激光器具有转换效率高、光束质量好、散热方便、结构紧凑等优点,是高功率激光器领域的研究热点。本文设计了温控、水冷系统使半导体激光二极管泵浦源稳定在工作波长。通过设计的包层泵浦功率剥除器,有效地剥离了未被掺镱（Yb3＋）双包层光纤吸收的泵浦光。采用20w的半导体二极管激光器作为泵浦源,5m长掺镱（Yb3＋）双包层光纤作为增益介质,光纤光栅作为腔镜,在泵浦功率为19w时,获得10．42W的激光输出,激光波长1062nm,光一光转换效率约54．8％。