1.48μm泵浦EDFA的研制及其在模拟光纤传输系统中的应用

利用国产１．４８μｍ泵浦ＬＤ和优质掺饵光纤研制了一种实用化的掺饵光纤放大器，小信号净增益２８ｄＢ，噪声系数５．１ｄＢ，增益谱宽大于２０ｎｍ，最大输出功率达４．８ｄＢｍ和１１ｄＢｍ。实验研究了ＥＤＦＡ在ＦＭ／ＦＤＭ模拟电视光纤系统的应用，利用ＥＤＦＡ作为系统的功率提升和中继放大器，分别成功地进行了１８５ｋｍ和２２４ｋｍ的系统传输试验。     

实用型1.47μmLD泵浦掺Er~3+光纤放大器模块

在国内首次采用国产１．４７μｍ激光二极管和掺Ｅｒ３＋／Ａｌ３＋光纤研制成光电一体化的光纤放大器实用型模块样机。模块净增益２７ｄＢ，饱和输出功率０ｄＢｍ，最大输出功率７ｄＢｍ，光学带宽＞２０ｎｍ，噪声系数＜７ｄＢ，可供光纤通信和光孤子传输实验系统试用。     

10频道“波分复用＋光纤放大器”全光通信实验系统

在国内首次研制了使用１个光纤放大器的１０频道１０２ｋｍ无再生中继“ＷＤＭ＋ＥＤＦＡ”全光光纤传输实验系统。每频道传输码率为１４０Ｍｂ／ｓ或２８０Ｍｂ／ｓＮＲＺ。所用光纤放大器为增益平坦型，小信号增益为３５ｄＢ。系统全部采用国产ＤＦＢ激光器，各频道波长分别为１５３１、１５３５、１５３７、１５４５、１５４７、１５４９、１５５１、１５５９、１５６１ｎｍ，在波长为１５５１ｎｍ的频道内布置了２路频分复用（ＦＤＭ）系统。波长分布遍及整个光纤放大器的通带。经无再生中继传输１０２ｋｍ后，在误码率为１×１０￣（－９）条件下，实测了尚有数ｄＢ以上（最大为１２ｄ８）的功率裕量。系统使用光栅合、分波器作为波分复用和解复用器，频道间隔为２ｎｍ及其整数倍，系统具有１８个频道的能力。     

23mW 33dB光纤放大器模块的研究

报道了高功率掺饵光纤放大器模块的研制。它采用低掺杂Ｅｒ／Ｇｅ／Ａｌ光纤作为放大媒介并采用１．４８μｍ以向激光泵浦结构，模块小信号增益３３ｄＢ，最小噪声系数５．１ｄＢ最大输出功率２３ｍＷ。     

带宽〉40nm的980nmLD泵浦掺Er^3＋光纤放大器模块

在国内首次用９８０ｎｍ激光二极管和参量优化Ｅｒ３＋／Ａｌ３＋共掺杂光纤研制成光学带宽＞４０ｎｍ的光电一体化光纤放大器实用型模块样机。模块净增益２５ｄＢ，饱和输出功率０ｄＢｍ，最大输出功率８ｄＢｍ，噪声系数＜５ｄＢ，可供波分复用光纤通信系统和光孤子传输实验试用。     

掺杂离子在LHPG单晶光纤中的分布

用电子能量色散谱（ＥＤＳ）分析了Ｎｄ＾３＾＋，Ｅｒ＾３＾＋和Ｃｒ＾３＾＋等掺杂离子在ＹＡＧ单晶光纤中的分布，实验发现：掺杂离子的分凝系数不同，其分布规律也不同，根据晶体的溶液生长理论，导出了掺杂离子分布方程，它与实验结果相符较好。     

抑制等信道间距陆上干线光纤通信系统中光纤色散和四波混频效应的新方案

提出了一种用以克服等信道间距划分、波分复用（ＷＤＭ）＋掺饵光纤放大器（ＥＤＦＡ）陆上光纤通信系统中光纤色散和四波混频（ＦＷＭ）效应的新方案。采用１５５０ｎｍ处色散为－２．８９ｐｓ／ｋｍ／ｎｍ的小色散单模光纤（ｓｍａｌｌ－ｄｉｓｐｅｒｓｉｏｎｓｉｎｇｌｅ－ｍｏｄｅ－ｆｉｂｅｒ，ＳＤＳＭＦ）可避免严重的ＦＷＭ效应，同时利用ＩＴＵ－ＴＧ．６５２非色散位移光纤（ｎｏｎ－ｄｉｓｐｅｒｓｉｏｎ－ｓｈｉｆｔｅｄｆｉｂｅｒ，ＮＤＳＦ），在ＥＤＦＡ整个带宽范围内（１５３０～１５７０ｎｍ）补偿ＳＤＳＭＦ引入的负色散。采用此方案，一个１０路×１０Ｇｂ／ｓ、１０级ＥＤＦＡ级联的等信道间距（１ｎｍ）光纤通信系统，经近千公里的光纤传输后，ＦＷＭ和色散引入的恶化量将分别小于１ｄＢ。     

上转换氟化物光纤激光器

氟化物玻璃是一种性能优异的激光基质材料。本文介绍了稀土离子上转换发光的机理和光纤顺的基本结构，综述了近几年来对掺Ｔｍ＾３＋、Ｐｒ＾３＋、Ｅｒ＾３＋、Ｈｏ＾３＋和Ｎｄ＾３＋的上转换氟化物光纤激光器的研究和应用概况。     

（BiAl）YIG薄膜的生长感生磁各向异性

从理论和实验上分析了Ｆｅ＾３＋和Ｆｅ＾２＋对（ＢｉＡ）ＹＩＧ薄膜的生长感各向异性的贡献，掺Ｂｉ导致的生长磁感生各向异性，来源于Ｅｉ＾３＋改变了Ｆｅ＾３＋的零场劈裂，其大小取决于Ｂｉ＾３＋含量及在十二面体位的择优分布，高价离子和氧空位形成的Ｆｅ＾２＋在八面体位的择优分布，对生长感生磁各向异性也有贡献。     

用于氟化镓铟高数值孔径光纤的氟磷酸盐和氟锆酸盐和氟锆酸盐包 …

为了得到用于１．３μｍ光通讯窗口掺镨化镓铟（ＰＧＩＣＥ）高数值孔光纤，本文报道以ＺｒＦ４－ＢａＦ２－ＬａＦ３－ＡｌＦ３－Ｎａ（Ｌｉ）Ｆ－ＰｂＦ２（ＺＢＬＡＮ（Ｌｉ）Ｐｂ）和ＮａＰＯ３－ＢａＦ２－ＺｎＦ２－ＰｂＦ２（ＦＰＧ）玻璃作为包层材料，研究了芯和包层玻璃在物理性质和化学组分上的匹配性，差热扫描（ＤＳＣ）和电镜（ＳＥＭ）分析表明ＰＧＩＣＺ／ＺＢＬＡＮ（Ｌｉ）Ｐｂ虽在物理性质上匹配，但在化学组分不     

光纤水听器系统光纤传输噪声的自适应消除

传输光纤引入的偏振和相位调制噪声给光纤水听器远程传输系统带来严重影响.论文提出使用一个声压和加速度不灵敏的参考探头来获取传输光纤引入的公共噪声,并将该噪声进行自适应滤波处理来估计和消除传感探头中传输噪声的方案.实验结果表明,归一化最小均方误差(NLMS)自适应算法对冲击传输光纤引入的宽带偏振噪声抑制最大达20 dB;对传输光纤中大幅度的单频连续相位调制噪声抑制达20 dB;自适应滤波基本消除了传输噪声的影响,并且完整保留了传感探头中的仿真信号.实验同时证明,自适应噪声消除的结果优于直接将参考探头与传感探头信号相减的噪声抑制效果.     

Monitoring Bench and Procedure for Measurement of the Parameters of Multiport Fiber-Optic Couplers

A monitoring bench and procedure for measurement of the transmission matrix of (N × N)-type multiport fiber-optic couplers using mechano-optical scanning of the bench to achieve a high measurement rate are presented. It is shown that it is possible to measure the elements of the transmission matrix with error at most ±0.2 dB.     

SOA-based multi-wavelength source

A simple fiber laser configuration based on a semiconductor optical amplifier (SOA) is proposed for obtaining multi-wavelength oscillation at room temperature, in which a Sagnac loop mirror is used as the wavelength selective component. The SOA has a flat gain of approximately 23dB within a bandwidth of 12 nm at a small input signal power. The loop mirror was constructed using a 3dB coupler and polarization maintaining fiber (PMF). The output spectrum of the proposed laser can be adjusted by controlling the bias current of the SOA and is quite stable at room temperature. At a bias current of 150 mA, six lines are obtained with at least ?40 dBm output power and 25dB signal-to-noise ratio (SNR). The channel spacing and number of lines is determined by the length of polarization maintaining fiber (PMF) used in the loop mirror. The channel spacing of the proposed laser is 1.49 nm with a PMF 3 m. The multi-wavelength comb output can also be tuned by adjusting the operating temperature of the SOA. The multi-wavelength laser has the advantage of a simple configuration, stability at room temperature, a broad wavelength band, and no need for optical pump lasers.     

抑制噪声的宽带碲基掺铒光纤放大器性能分析

设计了一个带光隔离器的复合型宽带碲基掺铒光纤放大器（EDTFA）,通过对该结构模型下的速率方程和光功率传输方程组的数值模拟,理论研究了EDTFA在插入光隔离器后的性能变化。研究表明,通过插入光隔离器抑制反向传输的放大自发辐射（ASE）噪声,可以有效地改善宽带EDTFA的信号增益和噪声特性。在光纤激活长度240cm、铒掺杂浓度2000ppm和前向泵浦功率200mW下,光隔离器插入在最佳位置处时,1540nm～1600nm波段内16路信道小信号增益分别提高了0.8dB～5．9dB,噪声系数降低了0.2dB～2．2dB。研究结果对于新型宽带EDTFA应用于WDM通信系统中具有理论指导意义。     

All fiber on-axis coupling scheme between single mode fiber and GRIN fiber

In this paper we present a simple and novel method to maximize on-axis coupling efficiency to radially symmetric fibers without the need for extra free space optical elements. The method is based on inserting a segment of step-index multimode fiber (MMF), cleaved to a particular length, between the input fiber and the output fiber (OF). The MMF segment modifies the input field to match the guided modes in the OF. Using this technique we show that, by inserting an appropriate length MMF segment, it is theoretically possible to obtain a coupling coefficient as high as ?0.8 dB between a single mode fiber and a graded index ring-shaped fiber and ?0.32 dB for a multi-shell fiber. Our experimental measurements showed good agreement with theoretical predictions for the ring fiber.     

2.07μm光纤激光在弱湍流条件下的传输特性研究

本文报道了一种2.07μm波段可调谐主动锁模光纤激光并在室内模拟大气湍流条件下进行传输特性研究。增益介质为1.5 m长的掺钬光纤,主动锁模通过LiNbO3强度调制器在腔内引入周期强度调制实现。腔内引入非线性偏振旋转效应实现波长2058.4nm^2078.6nm可调谐。实验获得了稳定的基频锁模脉冲和10阶,24阶,48阶谐波锁模脉冲,对应频谱信噪比为66.79 dB、61.37 dB、54.82 dB和49.66 dB。锁模脉冲经过数字调制后在实验室内大气湍流模拟池中进行传输,分别获得了?T为70℃,140℃和210℃时三种湍流强度和背对背条件下的眼图;与背对背条件相比,在?T=210℃时光信噪比降低了9.14 dB。     

碳纤维/羰基铁粉复合涂层吸波效果及机理分析

在碳纤维表面化学镀镍,再将其与羰基铁粉混合制备成吸波涂层,对其吸波性能进行了测试.结果表明:在2～18 GHz内,碳纤维/羰基铁粉吸波涂层,最大吸收峰在5.92 GHz,此时反射率为-8.89 dB,反射率小于-5.00 dB的频宽为9.50 GHz;单层羰基铁粉涂层在相同厚度下,最大吸收峰为7.94 GHz,对应的反射率为-10.36 dB,反射率小于-5.00 dB的频宽为6.90 GHz;碳纤维与羰基铁粉混合后,涂层反射率小于-5.00 dB的频宽增大,有利于吸收雷达波.最后,对碳纤维/羰基铁粉吸波涂层的吸波机理进行了初步分析.     

Dual wavelength erbium-doped fiber laser using a tapered fiber

A tapered fiber is fabricated by heating and stretching a piece of optical fiber after the polymer protective cladding has been removed. An equidistant comb-like transmission spectrum, with a spacing of 1.6?nm and an extinction ratio of more than 5?dB, was obtained by the tapered fiber due to the multibeam interferences of the cladding modes. The tapered fiber was applied in a ring erbium-doped fiber laser (EDFL) to generate dual-wavelength lasing oscillations. The EDFL operates at wavelengths of 1557.0?nm and 1558.6?nm with a stable peak power and a signal-to-noise ratio of more than 40?dB.     

Fiber optical based parametric amplifier in a highly nonlinear fiber (HNLF) by using a ring configuration

A four-wave mixing (FWM) effect in a fiber-based optical parametric amplifier (FOPA) is reported. The novelty in the setup used is a ring cavity as opposed to the commonly used method of linear cavity. This reduces the required pump power, P _p, for the amplification of the signals and also the generation of the idlers. The achieved gain for signal amplification is about 30?dB with a P _p of 25?dBm. It has a flat gain response within range of 22?nm from 1570?nm to 1592?nm, with an average value of 28?dB within the 3?dB region. The average conversion efficiency is approximately ?5?dB, with a peak value of ?4?dB within the 2?dB region, with a range of 24?nm from 1576?nm to 1600?nm.     

成组光纤水听器特性研究

成组光纤水听器具有能抑制流噪声、有指向性、灵敏度高等优点,可应用于全光拖曳阵.介绍了成组光纤水听器的概念,建立了其拾取水声信号的水声信号检测模型,理论分析了其灵敏度和指向性.完成了四子单元的芯轴型成组光纤水听器的光学设计和机械设计.在非消声水池中,采用脉冲法测定了其灵敏度和指向性.结果显示:此结构的成组光纤水听器灵敏度为-152dB(0dB=1rad/Pa),与理论值-151dB基本符合;当时,指向性函数主瓣宽度为28°,与理论值26°度基本吻合.