百纳秒级单频脉冲光纤激光极限功率的数值分析

建立了百纳秒级单频脉冲光纤激光极限输出功率的理论模型,分析了影响Yb3+掺杂的硅玻璃光纤和磷酸盐光纤最大输出功率的影响因素,计算结果表明影响硅玻璃光纤极限输出功率的因素有抽运光亮度、透镜效应和受激布里渊散射(SBS)效应,而对于磷酸盐光纤除了上述三种因素外还包括纤芯的熔化。在单频脉冲极限输出功率方面磷酸盐光纤的性能要优于硅玻璃光纤。     

Online ef fective backscattering estimation for ring laser gyro

Lock-in phenomenon in ring laser gyroscopes is directly related to effective backscattering,which includes both backscattering and nonuniform loss.Effective backscattering often differs in different states and can only be reflected in a working state via online estimation in the working state.Moreover,effective backscattering can result in the intensity modulation of beams in the opposite directions.The effective backscattering parameters can be obtained by measuring the weak modulations in the intensity signals under different rotation rates and by using the curve-fitting method.This letter demonstrates the online estimation of backscattering.     

吖啶橙共振光散射法测定脱氧核糖核酸

研究了吖啶橙与DNA作用的共振散射光谱,发现在pH 11的碱性溶液中痕量核酸对吖啶橙的共振散射光产生增强作用,且增强程度与核酸浓度之间有良好的线性关系。据此建立了测定核酸的高灵敏共振光增强分析方法。其最大散射波长均位于324 nm处,测定鱼精DNA(fs DNA)的线性范围是3.1×10-8～7.3×10-6 g·mL-1,检测限20.5 ng·mL-1,测定小牛胸腺DNA(ct DNA)的线性范围是7.5×10-8～9.8×10-6 g·mL-1,检测限20.8 ng·mL-1。该方法简单,操作方便,选择性好,灵敏度高,用于合成样品的测定结果满意。     

纳米尺寸的ZnO晶体高压相变的拉曼散射研究(英文)

Weperformedthehigh-pressureRaman measurementofthethreenanosizedZnOcrystals. Wefoundthesmallerthesize,thehigherthe pressuretoinducethephasetransitionfrom w櫣rzitetorock-saltstructure. High-pressureRamanmeasurementsof nona-shapedZnOcrystalswerepreformed.The…     

Controlled morphology of Ag nanocolumns by oblique angle deposition： kinetic Monte Carlo simulation

Fabrication of Ag or Au nanocolumns by oblique angle deposition （OAD） is now prevalent for their surface enhanced Raman scattering （SERS） property and their biosensor application. However, the size, shape, and the density of nanocolumns are not directed in a desired way. To sufficiently realize the growth process controlled by multiple physical factors like deposition angle （a）, substrate temperature （T）, and deposition rate （F）, we develop a three-dimensional （3D） kinetic Monte Carlo （KMC） model for simulating processes of Ag nanocolumnar growth by oblique angle deposition. The dependences of nanocolumnar morphologies on these factors are analyzed. The mimical results reach a reasonable agreement with the experimental morphologies generated bv OAD.     

混浊介质中线偏振光和圆偏振光的后向漫散射特征

以标准的组织模型Intralipid脂肪乳溶液为研究对象,采用CCD偏振成像系统,通过测量该混浊介质的后向漫散射光的斯托克斯矢量,深入研究了不同方位的线偏振光及不同旋向的圆偏振光入射时,后向漫散射光的特征.研究结果表明：对不同的入射偏振态,后向漫散射强度、偏振度的空间分布具有方位选择性,强度和偏振度的大小随距离入射点的距离增加而减小;介质浓度增加,后向散射强度增加,偏振度减小,且同一浓度下,圆偏振光的偏振度总是高于线偏振光.     

单壁碳纳米管-聚合物复合材料的拉曼光谱表征(英文)

本文在粗糙金属表面上制作了单壁碳纳米管—聚乙烯醇复合材料,并利用表面增强拉曼散射讨论了碳纳米管与聚乙烯醇之间的相互作用     

Influence of Ba^2＋ and Pb^2＋ Ions on the Raman Dominating Active Vibronic Mode in Strontium Nitrate Crystals

The compositions of Sr(NO3)2 crystals grown from an aqueous solution doped with Ba^2 and Pb^2 were characterized by the electron probe microanalysis technique.It was found that Ba^2 is enriched in {100} sectors and Pb^2 in {111} sectors.The Raman spectra of different parts of these crystals at room temperature in the ranges of 1038-1070cm^-1 and 650-1150cm^-1 were investigated.The results indicated that barium and lead shift the Raman dominating peaks to the lower frequency and broaden the full width at half maximum.Furthermore,barium probably degrades the properties of the Sr(NO3)2 Raman shifter while lead is anticipated to improve it.     

光纤-氮系统的受激拉曼散射

在实验上,对三种不同长度的石英光纤进行了高温高压扩氮制成了光纤氮拉曼增益介质,给出了测试SRS光谱的实验装置、光谱及传输模式照片.在理论上和实验上讨论了阈值条件和谱线宽度与抽运光功率之间的关系,实验结果和理论计算基本符合.同时,在实验上还观测到微弱的氮分子和石英分子间的耦合模式. 关键词： 光纤-氮系统 受激拉曼散射 传输模式 阈值条件     

三维可穿透目标远场声波反演的一种指示器样本方法

提出了用时谐声散射场的远场信息来可视化三维可穿透目标的一种指示器样本方法,它是通过析取一个指示器函数在包含可穿透目标的某个样本区域中的支集来实现这种可视化的,其中,这个指示器函数在可穿透目标的内部和外部有显著不同的取值.这个算法的一个特别吸引人的性质是不需要关于障碍物的任何几何和物理的先验信息,并且只需要散射场在某个有限孔径中若干个入射和测量方向上的远场信息,即可得到可穿透目标的一个很理想的可视化.数值算例保证了这个可视化算法是有效和实用的 关键词： 声散射 反问题 物形反演