优化二元相位取样光纤布喇格光栅及对色散和色散斜率补偿的应用

利用粒子群算法对二元相位取样光栅的周期相位调制进行优化设计，在此基础上提出了基于二元相位取样光纤布喇格光栅的色散和色散斜率补偿技术.通过光栅周期啁啾可以调整每个信道的带宽，色散量由子光栅长度决定，调整取样函数的啁啾系数可以改变色散斜率，因此可以设计出用于波分复用系统的多信道色散补偿器件.     

啁啾sinc取样光纤光栅研究

提出了一种特殊的取样光纤光栅：啁啾sinc取样光纤光栅.研究表明,对于均匀光纤光栅进行啁啾sinc取样,可以实现色散斜率补偿和获得精确的反射波长数控制;对啁啾光纤光栅进行啁啾sinc取样,则能够实现色散和色散斜率的同时补偿,并且可以进行精确的波长数控制及获得各信道一致的反射率.利用啁啾sinc取样光纤光栅,可以对各种传输光纤进行色散和色散斜率的补偿.     

低串扰的多波长光纤光栅色散补偿器

分析了光纤光栅色散补偿系统中的串扰，并比较了几种常用的多波长光纤光栅色散补偿器的串扰特性，结合串联的窄带光纤光栅和取样光纤光栅的优点，提出一种抑制光纤光栅色散补偿系统串扰的方法.它通过在邻近信道间引入随机时延差，既能改善取样光纤光栅的线性串扰特性，又能抑制交叉相位调制效应和四波混频等非线性串扰.使用该方法可以得到具有低串扰的多波长光纤光栅色散补偿器.     

基于啁啾光纤光栅的色散管理

本文通过数值仿真对基于啁啾光纤光栅的单信道的色散管理进行了研究，并在1500km的10Gb/s单信道传输系统中进行了实验验证.本文还通过分析啁啾光纤光栅引入的信道间随机时延差对交叉相位调制的抑制作用，发现了基于啁啾光纤光栅的多信道系统的色散管理的新的特点. 关键词： 光纤通信 色散补偿 啁啾光纤光栅     

取样光栅各参量变化对反射谱影响规律的研究

基于耦合模理论,采用传输矩阵法,模拟分析了均匀取样光栅的长度L、周期LA、折射率调制量δneff、啁啾系数f等参量对其反射谱的影响规律,研究了其在多信道色散补偿中的应用.研究和分析表明,取样光栅具有极好的波长选择性,在它的反射谱中通道多且通道间隔稳定,带通窄.在多信道色散补偿中,啁啾取样光栅各个信道的反射谱和时延曲线具有很好的一致性,色散量比较均匀,可以达到1 300 ps/nm,时延抖动小于50 ps.     

级联长周期光纤光栅对的干涉谱分析及其在多信道滤波器中的应用

分析了由光纤级联的两个相同的长周期光纤光栅形成的干涉谱。根据设计中的关键技术,利用粒子群优化算法设计了长周期光纤光栅传输损耗为50％的平坦传输损耗谱.将相同的两个优化设计的长周期光纤光栅级联,可以实现一种实用的可调谐多信道隔离滤波器.讨论了级联长周期光纤光栅对之间光纤的偏振特性对干涉谱的影响.     

16×10Gb/s啁啾光纤光栅色散补偿系统性能研究

运用啁啾光纤光栅法对在G.652光纤传输的16×10 Gb/s信号实现色散补偿数值模拟和研究,分析了入纤光功率、色散斜率以及啁啾光纤光栅色散补偿带宽对系统误码率的影响,结论是:入纤光功率在8～16 dBm之间时系统的性能较好;啁啾光纤光栅的色散补偿带宽对系统的影响较大;光纤的色散斜率对系统误码率有一定的影响.     

4×10 Gb/s 412 km密集波分复用光纤光栅色散补偿的实验

研制了一种多波长啁啾光纤布拉格 (Bragg)光栅 ,波长、波长间隔符合ITU T标准 ,利用这种多波长啁啾光栅可以同时对多信道波长进行色散补偿 ,光栅的每个波长补偿范围满足ITU T对应信道波长波动的要求 ,并进行了 4× 10Gb/s、4 12km波分复用色散补偿实验 ,实验结果比色散补偿光纤模块要好 ,无误码功率代价都小于 2dB。     

基于二元光栅特征提取的相位展开方法

传统基于正弦光栅相位测量轮廓术中,相位因反正切运算而被截断在(-π,π]之间,需要利用菱形等相对相位展开算法进行展开,容易产生相位误差累计,甚至无法展开相位;或者利用投影辅助格雷码等额外结构光场来确定条纹级次,避免相位误差累计,实现相位的展开.提出了一种基于二元光栅特征提取的相位展开方法.通过投影一组相移二元光栅来实现...     

光纤光栅非线性时延对啁啾的电视信号的影响

分析了有线电视系统中,用作色散补偿的光纤光栅因色散抖动对信号载波互调比产生的影响,结果显示色散抖动对有线电视信号互调比的影响随拦动幅度、抖动周期、信道数目的加而增加,信道频率的分布也对其的影响。对光栅的色散特性进行数值估算,发现常耦合系数线性啁啾光栅不能用的有线电视系统中进行色散补偿。     

A comprehensive study of the chromatic dispersion measurement of the multi-channel fiber Bragg grating based on an asymmetrical Sagnac loop interferometer

A novel all-fiber asymmetrical Sagnac loop interferometer (ASLI) is proposed to measure the chromatic dispersion of a multi-channel fiber Bragg grating (FBG). Theoretical analyses to this proposed approach are presented in details. With this method, the chromatic dispersion and dispersion slope of a 51-channel FBG are simultaneously measured. The experimental results agree well with the ones obtained by using the general phase-shift method (PSM). This method has the advantages of simple configuration, low-cost, and high tolerance for the characteristics of FBG.     

Analysis of fiber Bragg grating with exponential–linear and parabolic taper profiles for dispersion slope compensation in optical fiber links

In this paper, the effect of various taper profiles on dispersion slope compensation in optical fiber links is studied. Theoretical and numerical investigation of the linear and nonlinear group delays of tapered fiber Bragg grating's (T-FBG) under strain is made. Calculation is performed using Matlab code based on solving the coupled mode equation using transfer matrix method. Our study shows that the linear tapered FBG profile provide the best result than the linear-exponential profile which can compensate up to 500 km. As result, the spectral characteristics of tapered grating allow them to be used efficiently in high bit rates WDM and long-haul optical communication systems for chromatic dispersion of single-mode fiber.     

一种基于Optisystem的静态与动态色散补偿相结合方案研究

介绍色散补偿光纤DCF及动态啁啾光纤光栅FBG的补偿技术并比较其优缺点,提出在传统光传输系统末端加入动态FBG的方案,通过Optisystem仿真软件搭建40 Gbit/s的光传输系统,用FBG仿真光传输400 km的Q值为3.745,误码率为7.419 42e-5,用DCF静态混合补偿和静态与动态相结合的补偿方案分别仿真并比较两种方案传输相同距离的Q值和误码率的大小,证明提出的静态加动态的方案提高了光传输性能。     

A High Efficiency Yb3+-doped Fiber Ring Cavity Laser with Narrow Line-widthRound-trip Dispersion Calculation for Martinez Pulse Stretcher

A novel Yb3+-doped fiber ring cavity laser pumped by a 977 nm laser diode is presented with its output laser wavelength of 1060 nm. Based on a fiber Bragg grating (FBG), the laser exhibits 0.20 nm line-width, 7.5 mW laser output power, 40 dB signal-to-noise ratio (SNR) and 66% slope efficiency.This paper proposed a ray-tracing model for the Martinez stretcher, derived the calculation formulae for the stretcher of a grating-spherical mirror system and discussed the error for the total dispersion resulted from the spatial dispersion. The calculated results show that the error could be ignored for the beam returned to the stretcher for the second pass in the wavelength range of 750 nm and 850 nm.     

光纤光栅双折射效应的实验研究

本文对均匀光纤光栅和线性啁啾光纤光栅的双折射效应分别进行了实验研究. 利用压电陶瓷的压电效应实施对均匀光纤光栅和线性啁啾光纤光栅的侧向挤压, 使之产生双折射, 通过改变施加在压电陶瓷上的电压值, 可以实现对光纤光栅双折射大小的控制. 侧向挤压线性啁啾光纤光栅可以补偿光纤通信系统中的偏振模色散.     

Fabrication of high quality chirped fiber Bragg grating by establishing strain gradient

To fabricate chirped fiber Bragg grating (CFBG) with high reflectivity and accurately controlled chirp profile with low cost, we develop the CFBG fabrication technique based on strain gradient: fabricating CFBG using fabricated fiber Bragg grating (FBG) by establishing strain gradient along the length of grating. We theoretically analyze the form of such CFBGs, and study the characteristics of gratings using piecewise-uniform approach. It is shown that increasing UV-induced index change or the length of the grating or both are the efficient ways to obtain high quality CFBG with high reflectivity and good reflection spectrum. The dispersion of this grating is decided by and varies inversely with the slope of the strain gradient along the length of the grating, not decided by UV-induced index change or by the length of grating. One can control the dispersion and the chirp profile by adjusting the slope of the strain gradient. Based on the theoretical analysis, we have fabricated CFBG whose reflectivity is maintained at 100% in a large range of strain gradients.     

基于色散调谐宽带扫频光纤激光器及其在光纤光栅解调中的应用

报道了一种基于色散调谐技术的宽带扫频掺铒光纤激光器。通过在主动锁模光纤激光器腔内引入较大色散,利用锯齿波电信号调制电光调制器的调制频率,可以实现激光器扫频输出。应用扫频激光器可将光纤光栅反射中心波长的变化转变为时域上信号间隔变化,适用于光纤光栅传感解调。搭建了扫频光纤激光器,利用掺铒光纤作为增益介质,研究了扫频范围的影响因素。通过优化实验参数,实验得到的扫频带宽达到43 nm,接近增益带宽,扫频速度为50 Hz。利用搭建的扫频激光器进行了光纤光栅传感解调,灵敏度约为0.68 ms/nm,验证了解调原理。