石英光纤中二次谐波的产生及机理分析

报道了采用预置法使石英光纤中产生二次谐波及由透射电子显微镜预置前后光纤内部物质结构变化的实验结果，发现石英光纤中存有少量晶体，正是它们在预置前后的结构变化导致了二次谐波的产生。     

石英玻璃光纤表面化学镀镍

采用化学镀的方法在石英玻璃光纤表面上制备了光亮、均匀、可焊性好的镍镀层；在光纤表面粗化后增加热处理工序可以克服石英光纤表面难以活化的问题。     

普通单模石英光纤中频率上转换过程的研究

介绍了在普通通讯用单模ＧｅＯ２／ＳｉＯ２石英光纤中从近红外到可见光的频率上转换过程。利用１．３１３μｍ的调Ｑ锁模Ｎｄ：ＹＬＦ激光脉冲泵浦单模石英光纤，产生了５８８ｎｍ的黄光，峰值功率达２０Ｗ，对应０．０９％的转换效率。     

熔石英棒-光纤组合型相位共轭镜的研究

提出了一种由大口径的熔石英棒和较大芯径的光纤组成的相位共轭镜.在光纤中产生的斯托克斯(Stokes)种子光经由熔石英棒放大后输出.该相位共轭镜可以用于高重复频率激光系统中以改善激光光束质量.实验中,在重复频率100 Hz的情况下,最大获得了42.05%的受激布里渊散射反射率,光束质量从3降低到1.6;在重复频率400 Hz的情况下,光束质量从4降到了1.7.根据实验条件建立的理论模型经数值求解后与实验结果拟合较好,并由理论推导提出了一种提高该复合型相位共轭镜工作状态的有效方法.     

基于飞秒激光的光纤切割加工工艺研究

为了得到理想的光纤切割断面,利用飞秒激光对石英光纤材料进行切割微加工实验。研究激光功率、脉冲频率、扫描速度等加工参数与光纤切割断面质量间的关系,以寻求最理想的加工参数。最后在可调倾角光纤夹具的辅助下,很好地弥补加工过程中产生的端面倾斜角,得到垂直度高达89.56°的光纤切割断面。     

石英光纤γ辐照损伤及其对近红外导波特性的影响

围绕光纤陀螺的近红外工作波长,从回波损耗、偏振相关损耗、散射损耗、吸收损耗、模场分布以及导模传播常数等方面实验考察了总剂量为120krad(1.2kGy)的γ辐照对石英单模光纤导波特性的影响;用近红外光谱技术和受激喇曼散射实验估计了相应的隙内缺陷能级及其增量;用X衍射考察了介质密度变动;采用高灵敏度干涉回路观察到了γ辐照光纤的光热效应,测试数据表明紫外退火具有一定的修复作用,揭示了紫外退火作为一种主动加固方式用于抗γ辐照的可能性.     

大芯径紫外石英光纤γ射线辐照效应研究

阐述了三种不同芯径的紫外石英光纤的稳态γ射线辐照效应,对比研究了其发光特性、光谱衰减以及光谱展宽。设计了基于钴-60源的大芯径紫外石英光纤稳态γ射线辐照效应实验,对三种芯径(200μm,400μm和600μm)的光纤进行了研究。实验表明,大芯径紫外石英光纤在稳态γ射线辐照下存在稳定的发光现象,并对其光谱衰减有补偿作用,其光谱展宽效应不明显。     

用于高功率系统的掺镱石英光纤研究进展及发展趋势

掺镱石英光纤是掺镱光纤激光器及放大器的重要基础元件.掺镱光纤性能提升是促进掺镱光纤激光器系统功率进一步攀升的关键.本文回顾了高功率掺镱光纤激光器系统功率攀升情况及功率限制性问题,简述了针对激光功率攀升的瓶颈问题所提出的改善性方案.重点阐述了掺镱光纤制备技术、光纤材料、结构性设计在改善功率限制性方面所取得的研究进展,并对未来掺镱石英光纤的研究及发展趋势进行了展望.     

空腔铜靶的化学镀制研究

介绍了在预处理芯轴(聚甲基丙烯酸甲酯)表面采用化学镀的方法制备铜空腔的技术,研究了镀液中硫酸铜含量、甲醛含量,镀液pH值、温度等对化学镀铜沉积速率和溶液稳定性的影响。根据实验确定了适宜的化学镀铜工艺规范：硫酸铜质量浓度10~20 g/L,TART·K·Na质量浓度10~30 g/L,EDTA·2Na质量浓度10~28 g/L,甲醛体积浓度10~25 mL/L,添加剂质量浓度10 mg/L,pH值12~13,温度35~65 ℃。通过该工艺制备出的镀层厚度达到10～25 μm,均匀性达到95%,表面无砂眼、裂纹等缺陷,刻蚀芯轴后空腔能自持。该方法为ICF研究制备金属或合金材料靶提供了新的途径。     

A novel process for electroless nickel plating on anodized magnesium alloy

In this paper, a novel palladium-free activation electroless nickel (EN) plating process, by which a TiB₂ powders contained intermediate film was used as catalyst, was introduced for anodized magnesium alloy AZ91D. The corrosion behavior of AZ91D without and with coating was compared and the bonding strength of the EN plating to the substrate was also measured. The results showed that the EN plating could easily take place on the intermediate catalytic layer, directly on which a smooth and compact Ni–P alloy layer without obvious flaws, about 20 μm thickness, was successfully deposited. The catalytic function was principally from TiB₂ powder. The adhesive tensile test indicated a good bonding strength of about 11 MPa between the substrate and the catalytic layer. An obvious passivation range and higher E_corr (−0.323 V) for the EN plating during anodic polarization in 3.5 wt.% NaCl solution, implied a typical character of a compact Ni–P alloy layer, with an effective protection for the substrate.     

Microwave-assisted activation for electroless nickel plating on PMMA microspheres

A novel microwave-assisted activation method for electroless plating on PMMA microspheres is presented in this study. When the microwave irradiation was applied during the activation step, the amount of the Pd species adsorbed on PMMA surfaces was much higher than that of sample pretreated with a conventional activation process without microwave irradiation. With this activation method, it was also shown that the adsorbed Pd species with a size of 4-6 nm were uniformly distributed on the surfaces of the PMMA microspheres, thus a smooth and uniform nickel-phosphorus coating on the PMMA microspheres was obtained by subsequent electroless plating. The samples after each step were characterized by XPS, TEM, ICP and SEM.     

磁性ICF靶丸的化学镀工艺制备与表征

采用化学镀工艺在ICF聚苯乙烯靶丸表面包覆了一层磁性的Ni-P合金镀层,并分别用扫描电子显微镜、能谱仪、X射线衍射仪以及振动样品磁强计对其形貌、组成、结构和磁性能进行了表征。结果表明：通过化学镀工艺制备的Ni-P合金镀层厚度约为4 μm,且为非晶结构,并具有一定的磁性;该磁性ICF靶丸可望用来进行磁悬浮实验研究。最后,对聚苯乙烯靶丸表面磁性涂层的制备机理进行了讨论。     

Incorporation of nano zinc oxide for improvement of electroless nickel plating

The advantages of electroless nickel plating (EN) include excellent corrosion resistance, wear resistance, solderability, low porosity and uniform thickness even on complex parts and ability to plate on nonconductors. In the present study nano ZnO particles were synthesized by using an electrochemical technique and incorporated the particles into Ni-P plates. An alkaline bath was selected and used for nano zinc oxide incorporation. The electrochemical and metallurgical properties of the Ni-nano ZnO-P plates were evaluated and compared with that of the un-reinforced Ni-P plates. The incorporation of the nano ZnO particles resulted in improvement of metallurgical and corrosion resistance characteristics of the plates.     

Creep deformation measurement using quartz optical fiber

This paper describes an optical system for high temperature creep strain measurement using quartz optical fiber, super long working distance microscope and digital image processing techniques. In this system one end of the quartz optical fibers is arrayed in a small area on the specimen surface and the other end is illuminated by a laser beam. The fiber ends on the specimen surface form the spot array. The small optical spots on the specimen are tracked by a CCD camera and the images are processed by digital image processing software. The diameter of each quartz fiber is 100 μm and the fibers can be arrayed in a small area. The local strains are determined by measuring the variety of relative distance between two spots. Experimental results of local creep strain on the welding joints of 15CrMo and HK40 at 850°C are obtained.     

软X射线掠射筒状反射镜镀镍磷合金的研究

在软X射线掠射光学系统筒状反射镜的加工过程中,根据对反射镜内表面镍磷合金镀层的质量要求,采用镍盐还原法对筒状微晶玻璃反射镜的内表面进行了活化,并对在含有30g/LNiSO4.6H2O、30g/LNaH2PO2.H2O、25g/LNa(CH3COO).4H2O、18g/LC6H8O7、10mg/L添加剂的镀液中沉积镍磷合金镀层的工艺方法进行了探索。对得到的镍磷合金镀层的结合力、抗腐蚀能力等进行了测试。结果表明,采用此法镀制的镍磷合金镀层结合力达到4B级,耐蚀性好,能够满足光学精密抛光的要求。     

Influence of surface treatment on the electroless nickel plating of textile fabric

The present study is performed with an objective to acquire a deeper understanding of the properties of nickel-plated polyester fabric after conducing low temperature plasma treatment. Low temperature plasma treatment with oxygen and argon gases was employed to render a hydrophilic property of woven polyester fabrics and facilitate the absorption of a palladium catalyst in order to provide a catalytic surface for electroless nickel plating. The properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by various standard testing methods in terms of both physical and chemical performances.     

Nd：YAG单晶光纤光学特性研究

本文测量了用激光加热基座法拉制的Nd:YAG单晶光纤(具有块状晶体)的吸收谱线,荧光谱线等光谱学特性.根据测得的散射特性分析了用该法拉制的单晶光纤的生长缺陷和直径波动及其与单晶光纤质量的关系.