测量光纤放大器小信号增益谱的一种简便方法

提出了一种用小功率宽带光源较精确测量光纤放大器小信号增益谱的方法。数值模拟表明 ,该方法是完全可行的 ,并且实验结果与数值模拟结果一致。该方法具有简便、易操作的特点。     

ZnS:Er量子点材料制备及其受激发光特性研究

在水性介质中,制备了ZnS：Er量子点,并对其的X射线（XRF）谱、X射线衍射（XRD）谱、透射电子显微镜（TEM）图像和光致发光（PL）谱进行了研究,确定了所制备的ZnS：Er量子点材料中Er的浓度,观测到ZnS：Er量子点呈粒径为4nm的近球型结构。利用LD激发,在LD不同电流强度下得到ZnS：Er量子点从波长1500nm到1650nm的宽谱发射,并随着电流强度的增加ZnS：Er量子点的发射强度明显增加,当电流强度达到1．5A时,1545nm波长处的发射峰更明显。     

基于FBG的多级延迟SBS结构的慢光系统研究

设计一种基于光纤布拉格光栅(FBG)的多级延迟受激布里渊散射(SBS)结构的慢光系统.实验中采用2个FBG和一段15 km标准单模光纤(SSMF),利用光栅不同的反射特性,使信号光和泵浦光可重复通过同一段光纤相互作用,在仅使用一段光纤情况下达到双级时延的效果,并且FBG对信号光同样具有一定的延迟.实验结果表明,在展宽S...     

偏振无关的全光纤窄带通梳状滤波器

提出了一种基于二阶高双折射光纤(HBF)Sagnac环Sagnac环镜的全光纤窄带通梳状滤波器。二阶HBFSagnac环镜由单环构成,环中包含2段HBF。对照由2个一阶HBFSagnac环镜级联实现的窄带通梳状滤波器,进行了理论推导和试验证明。结果表明,当二阶HBFSagnac环镜中的2段HBF的长度设定为L1∶L2=1∶2,入射光与HBF快轴间的夹角为θ1+θ3=45°、θ2=45°时,实现了类似于2个一阶HBFSagnac环镜级联的传输谱,具有窄带通和宽信道间隔的特点。与对照的方案相比,边模抑制比高出3dB,此外还具有插入损耗低、实现简单等优点。理论推导与实验结果吻合。     

Multimode oscillation Q-switched erbium-doped fiber laser with a few-mode fiber cavity

We propose and demonstrate experimentally a multimode oscillation Q-switched erbium-doped fiber laser with a few-mode fiber cavity. The different coupling processes of reflection peaks of fiber Bragg gratings (FBGs) which act as cavity mirrors allow the different oscillating states. We obtain microsecond light pulse output states whose oscillation and output beams have different mode compositions, including high order mode. Such a structure enables the high order mode oscillation in the whole cavity with an all-fiber structure, which has potential applications in mode-division multiplexed systems and research of multimode nonlinear effect.     

Fiber laser twist sensor with hybrid few-mode tilted Bragg grating and few-mode long period grating

A twist sensor with hybrid few-mode tilted fiber Bragg grating (FM-TFBG) and few-mode long period grating (FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is used for sensing. The transverse modes at 1 553.9 nm and 1 550.5 nm are LP01 and LP21 core modes, respectively, which are coupled from forward-propagating LP11 core mode. These two excitation wavelengths have opposite variation tendencies, which participate in sensing. The twist sensitivity of 0.16 dB/° from ?40° to 40° is achieved. The proposed sensor has potentially used for structure monitoring in many areas.     

微结构光纤激光器件

由于微结构光纤灵活多变的结构特点,使得以其为增益介质的光纤激光器件,具有比普通光纤激光器件更加优异的性能.本文结合国际上微结构光纤激光器件的最新研究进展情况,概述了微结构光纤作为增益介质的独特特性、微结构光纤激光器件的理论分析方法和掺铒、掺镱以及喇曼微结构光纤激光器件的特点.     

光纤布拉格光栅的半金属管封装及挠度实验研究

本文提出了一种基于光纤布拉格光栅的半金属管封装方案 ,利用标准悬臂梁进行了挠度试验测量 .结果表明 ,用半金属管封装技术可以使光纤光栅感测的实验值更接近理论计算值 .封装后的实验测量值可达到理论值的94 %以上 ,FBG的挠度传感灵敏度约为± 0 .0 2 ,其对称性亦很好 ,线性拟合度分别达到 0 .995 8和 0 .9977.     

Nonlinear propagation of pulses in multimode fiber with strong linear coupling

Multimode fiber has a richer spatial dimension than single-mode fiber, and is an ideal platform for studying many novel nonlinear effects. We established a strong linear coupling and short-range fiber model to understand the interactive effects of linear coupling and nonlinear effects. We find that strong linear coupling can compensate for the group delay between eigenmodes and cause energy fluctuation between modes which weakens the nonlinear effects. In high energy pulses, the interaction of linear coupling and nonlinear effects can help producing weak dispersion waves when the spectrum is broadened. Since linear coupling in a mode group is common and unavoidable, these results may provide a certain theoretical explanation for multi-mode nonlinear phenomena.     

一种新颖的反射结构高功率超宽带光纤光源

报道了一种新型高功率超宽带光纤光源。利用980nm激光二极管(LD)和1480nmLD双向抽运掺铒光纤，经光纤环镜反射后，得到C L波段自发辐射谱。通过调整980nmLD和1480nmLD的功率，在1524．O～1600．6nm(76．6nm)范围内，自发辐射谱功率高于-18．8dBm，并且在1539．2～l600．6nm(61．4nm)范围内，自发辐射谱的平坦度为2．8dB。总荧光功率为22．1mW。转换效率为18．8％。如果不加环镜，并且保持相同的抽运条件，得到的放大自发辐射(ASE)谱宽在1525～1565nm的C波段范围，其总的荧光功率为7．1mW，转换效率仅为6％。通过分析加环镜情况与不加环镜情况下所得到的自发辐射谱，以及加环镜情况下采用不同的抽运方式得到的自发辐射谱，最终得出结论，通过加环镜，并且用980nmLD和1480nmLD双向抽运，得到了具有最佳效果的超宽带光纤光源。实验过程中通过调整980nmLD和1480nmLD的功率，曾得到28．5mW的荧光功率，转换效率为22．3％。