线性啁啾光纤光栅色散补偿性能的数值分析

对线性啁啾光纤光栅的色散补偿性能进行了数值分析。结果表明 ,啁啾光栅时延曲线的纹波大小和线性度是影响其色散补偿性能的两个重要因素。对高斯型耦合系数分布光栅而言 ,更长的光栅将具有更佳的色散补偿性能     

线性啁啾光纤光栅的优化设计

基于线性啁啾光纤布拉格光栅的色散补偿原理，探讨了不同的准高斯型耦合系数函数曲线对色散补偿特性的影响，建立使该光栅色散补偿曲线既具有高色散系数和宽带特点，同时对边峰还有相对的抑制能力的设计思想。文中讨论了相关参数对色散补偿曲线的影响。     

基于啁啾光纤光栅的掺Yb3+光纤激光器

啁啾光纤光栅可用于光纤色散补偿及脉冲压缩。该文从光纤光栅的耦合模方程出发，对中心波长为1053nm的啁啾光纤光栅进行了研究，数值分析了啁啾光纤光栅长度、耦合函数、啁啾系数、切趾技术等因素对啁啾光栅反射率、时延特性、色散特性、压缩特性的影响，并将结论应用于掺镱超短脉冲光纤激光器的设计，提出基于啁啾光纤光栅的全光纤环形腔连接方案。与其它非全光纤结构光纤激光器相比，这种结构具有更小的损耗和更高的效率。     

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。     

Chirped Bragg光纤光栅的优化设计与优化指数

根据线性ChirpedBragg光纤光栅的一般原理 ,探讨了不同啁啾系数 ,准高斯耦合函数对Bragg反射光栅的反射率及色散补偿特性的响应。结果表明 :增大啁啾系数以及选取适当的准高斯耦合函数 ,在保证反射率较大的情况下 ,能有效地改善色散补偿特性。通过引入微波领域的“优化指数”这一概念 ,量化了色散补偿器的补偿能力。     

高速光通信系统中光纤光栅色散补偿研究

通过对光栅制作过程的优化设计，解决了光纤光栅温度稳定性、纹波系数、带宽、偏振模色 散补偿等关键技术，所制作光纤光栅已经达到温度系数小于00005 nm/℃，带宽大于14 nm，纹波系数小于50 ps，色散量超过 -1000 ps/nm的先进水平. 采用琼斯矩阵本征值法较 精确地测量了光栅的偏振模色散，并对其进行了补偿，光纤光栅色散补偿器的偏振模色散由 补偿前的91406 ps改善为补偿后的01521 ps. 在此基础上，成功地建立了一个稳定可靠 、速率为40 Gb/s，传输链路为122 km G 关键词： 高速光通信系统 普通单模光纤 光纤光栅 色散补偿     

薄包层啁啾长周期光纤光栅的色散补偿

为了提高啁啾长周期光纤光栅(LPFG)光纤通信的色散补偿能力,提出了利用薄包层啁啾LPFG进行包散补偿的方法.首先介绍了根据传输信号确定啁啾LPFG的啁啾系数、光栅长度等参数的方法.然后利用上述方法设计了对光纤中传输的中心波长为1550 nm,带宽为0.2nm的信号进行色散补偿的薄包层啁啾LPFG.利用耦合模理论及传输矩阵法计算了约1m长的此种啁啾LPFG的色散,结果表明可以补偿该光信号通过46 km光纤所产生的色散.进一步分析了切趾函数、啁啾系数、交叉耦合系数等参数对薄包层啁啾LPFG色散的影响.     

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.     

光纤光栅偏振模色散的测量及补偿研究

介绍了光纤光栅的偏振模色散测量，并利用一段偏光纤对光纤光栅的偏振模色散进行补偿，效果良好。在40Gb/s、60km光纤光栅色散补偿系统中，加入保偏光纤对光纤光栅的偏振模色散进行补偿前后的测试结果表明，误码率为10^-10时，系统的功率代价由1.21dB改善为0.46dB。     

利用啁啾光纤光栅进行色散补偿的研究

分析了由于光纤的色散引起的脉冲展宽,并介绍了啁啾布拉格光纤光栅进行色散补偿的基本原理。２－５Ｇｂ／ｓ、１００ｋｍ 色散补偿的实验结果表明,利用啁啾光纤光栅进行色散补偿是一种切实可行的色散补偿方案。     

Dispersion Compensators Based on Overlaped Linearly Chirped Fiber Gratings for DWDM Systems

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Dispersion Compensators Based on Overlaped Linearly Chirped Fiber Gratings for DWDM Systems

By introducing a convergent lens in the phase mask setup and by tilting appropriately the fiber from the phase mask, a linearly chirped fiber grating with an appropriate chirp can be obtained conveniently. Using this method, two groups of fiber gratings, each of them is composed of 8 overlaped linearly chirped fiber gratings but with different center reflection wavelength separations (～0.8 nm and ～1.6 nm, respectively) are fabricated. Experimental results show that, the compensators based on the two groups of fiber gratings can be used to compensate for the dispersion of 8×2.5 Gb/s transmission over 100 km of standard single-mode fiber for multiple channels in optical time-division multiplexing (OTDM) and densed wavelength division multiplexing (DWDM).     

啁啾双光纤光栅群时延特性

研究了变迹线性啁啾双光纤光栅的群时延特性及其在高次色散补偿中的应用.分析表明,群时延特性与周期差ΔΛ和不同的啁啾参量C有很大的关系.研究结果表明啁啾双光纤光栅在高次色散补偿和光纤CDMA中有应用价值.     

Fiber-based tunable dispersion compensation

Tunable dispersion has been implemented in various technology platforms, including fiber gratings, planar waveguides, thin film etalons, and bulk optic technologies. This paper will focus on fiber grating based tunable dispersion compensation, because fiber gratings are at present one of the best developed TDC technologies available. The paper is divided into three parts. In the first part we describe grating based TDC technologies and discuss their advantages and disadvantages. We focus on thermally tuned linearly chirped fiber gratings, as these have to date been the most successful grating technology for 40 Gbit/s. We also compare grating TDCs to two other prominent tunable dispersion technologies: thin film etalons and planar waveguide ring resonators. In the second section we describe the techniques used to fabricate high performance dispersion compensation gratings as well as the theory of the primary defect of fiber grating dispersion compensation: group delay ripple (GDR). In the third section we describe the telecom system related issues for tunable gratings, including characterization of grating performance, tunability requirements and results from actual system trials using tunable FBGs.     

适合于有线电视系统的色散补偿光纤光栅

分析了光栅色散抖动对有线电视信号的影响,估计出落在信号50MHz-5550MHz范围内互调产物功率约占所有互调产物功率的10％－50％,为了抑制色散抖动幅度,光栅的折射率变化应该从初值零渐渐长到最大值。长度为10cm,包络为升余弦与tanh(4z)的光栅都能满足有线电视系统的要求,此外还发现,长光栅对应的抖动周期小,因此对信号的影响也小,具有升余弦包络的光栅比tanh(4z)光栅更能有效地抑制色散抖动。     

Modelling of linearly chirped fiber bragg gratings by the method of single expression

To model chirped fiber Bragg gratings (FBGs) for dispersion compensation in optical fibers a novel method of single expression (MSE) is used. The reformulation of Helmholtz’s equation in the MSE to the full set of first-order differential equations leads to dealing with the electric field amplitude, its derivative, power flow density and phase distributions in any aperiodic media. The phase derivative obtained numerically permits to compute the dispersion slope in the time delay of investigated chirped gratings. Reflective and time delay spectra of linearly chirped gratings of different lengths and chirp coefficients are computed. A self-similarity law for the gratings of the same strength but different lengths and chirp coefficients is revealed. The apodization of gratings is applied to reduce sidelobes in gratings’ reflection spectra and eliminate oscillations in the time delay characteristics.     

Modelling of linearly chirped fiber Bragg gratings by the method of single expression

To model chirped fiber Bragg gratings (FBGs) for dispersion compensation in optical fibers a novel method of single expression (MSE) is used. The reformulation of Helmholtz's equation in the MSE to the full set of first-order differential equations leads to dealing with the electric field amplitude, its derivative, power flow density and phase distributions in any aperiodic media. The phase derivative obtained numerically permits to compute the dispersion slope in the time delay of investigated chirped gratings. Reflective and time delay spectra of linearly chirped gratings of different lengths and chirp coefficients are computed. A self-similarity law for the gratings of the same strength but different lengths and chirp coefficients is revealed. The apodization of gratings is applied to reduce sidelobes in gratings' reflection spectra and eliminate oscillations in the time delay characteristics.     

啁啾光栅色散及时延特性研究

基于耦合模理论，通过对耦合波方程进行相位共轭变换，将反向耦合波方程变换为Ｒｉｃｃａｔｉ微分方程，利用数值解法对常耦合系数和高斯型耦合系数线性啁啾光栅的反射特性、色散特性和时延特性进行了详细分析，为设计具有理想效果的色散补偿器件提供了有效的理论方法。     

Strong phase-controlled fiber Bragg gratings for dispersion compensation

Dispersion-compensating fiber Bragg gratings with approximately 99.9% reflectivity that are made by continuous apodization and phase control are demonstrated. These strong dispersion-compensating gratings provide precision second-order, third-order, or even more complex dispersion compensation, as well as sufficient transmission isolation to be used at add-drop stages without additional filtering. A 99.84% grating with a constant approximately 700-ps/nm dispersion and a 99.94% grating with dispersion varying linearly from 1000 to -1000 ps/nm are demonstrated.