Realizing 20 Gbits OTDM Transmission over 50km Truewave Fiber with Dispersion Compensation

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｈｅｒｅａｒｅｔｗｏｍｅｔｈｏｄｓｔｏｅｎｈａｎｃｅｔｈｅｃａｐａｃｉｔｙｏｆｔｈｅｔｒａｎｓｍｉｓｓｉｏｎｓｙｓｔｅｍ：ｏｐｔｉｃａｌｔｉｍｅｄｉｖｉｓｉｏｎｍｕｌｔｉｐｌｅｘｉｎｇ（ＯＴＤＭ）ａｎｄｏｐｔｉｃａｌｗａｖｅｌｅｎｇｔｈｄｉｖｉｓｉｏｎｍｕｌｔｉｐｌｅｘｉｎｇ（ＷＤＭ）．ＯＴＤＭｉｓｂｅｉｎｇｗｉｄｅｌｙｒｅｓｅａｒｃｈｅｄｂｅｃａｕｓｅｏｆｓｏｍｅｖｉｒｔｕｅｓｉｎｏｐｔｉｃａｌｎｅｔｗｏｒｋｓ［１～４］．ＯＴＤＭｗｉｔｈｔｈｅｓｉｎｇｌｅｃｈａｎ…     

Numerical Study on the Performance in High bit rate Optical Communication Systems

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｄｅｓｐｉｔｅｔｈｅｇｒｅａｔｓｕｃｃｅｓｓｏｆｗａｖｅｌｅｎｇｔｈｄｉｖｉｓｉｏｎｍｕｌｔｉｐｌｅｘｅｄ (ＷＤＭ )ｓｙｓｔｅｍｓｉｎａｃｈｉｅｖｉｎｇｈｉｇｈ ｃａｐａｃｉｔｙｔｒａｎｓｍｉｓｓｉｏｎ ,ｔｈｅｒｅｒｅｍａｉｎｓｉｎｔｅｒｅｓｔｉｎｅｘｐｌｏｒｉｎｇｔｈｅｃａｐａｂｉｌｉｔｉｅｓｏｆｈｉｇｈｄａｔａｒａｔｅｉｎｓｉｎｇｌｅｃｈａｎｎｅｌｓｙｓｔｅｍｓ.Ｔｈｅｐｒｏｐａｇａｔｉｏｎｏｆｃｈｉｒｐｅｄｐｕｌｓｅｓｉｎｏｐｔｉｃａｌｆｉｂｅｒｓｉｓｏｆｇｒ…     

Broadband dispersion compensation of conventional single mode fibers using microstructure optical fibers

This paper presents a microstructure optical fiber for dispersion compensation in a wide range of wavelengths. The finite-element method with perfectly matched absorbing layers boundary condition is used to investigate the guiding properties. The designed novel dispersion compensating fiber shows that it is possible to obtain a larger negative dispersion coefficient of about −130 to −360 ps/(nm km), better dispersion slope compensation, better compensation ratio, and lower confinement losses less than 10⁻² dB/km in the entire telecommunication (1400–1600 nm) band by using a modest number of design parameters and very simple cladding design.     

系统中基于快速扫描光学延迟线的色散补偿

分析了光学相干层析成像(Optical Coherence Temography,OCT)系统中色散失配对系统纵向分辨率的影响,详细阐述了快速扫描光学延迟线(Rapid Scanning Optical Delay Line,RSOD)的色散性质,提出并采用基于RSOD的色散补偿方法,实验验证了这种色散补偿方法能够实现OCT系统的纵向分辨率接近于理论值,并因此得到了高质量的OCT图像.     

Femto-Second Transform Limited Pulse Generation with Higher Order Dispersion Effects for Dispersion-Shifted Optical Communication System

The paper deals with the influence of higher-order effects of dispersion on the femto-second transform limited pulse generation by compensating for linear chirp of self-phase modulation spectra in the dispersion-shifted fibers. It has been shown that the minimum propagation length with first-order dispersion term is 23 m, as reported earlier. If the higher-order dispersion effects are taken into consideration, this length is reduced to 11.5 m. With compensation of the first-order dispersion term, this length can be enhanced to 6.8161 × 10³ km. This length can further be improved to 6.0343 × 10⁹ km by compensation of first- and second-order dispersion terms together. The minimum pulse width and linewidth product without dispersion, with dispersion including higher-order dispersion effects, and with dispersion compensation, is found to be 0.44, 0.4418, and 0.4411, respectively.     

Femto-Second Transform Limited Pulse Generation with Higher Order Dispersion Effects for Dispersion-Shifted Optical Communication System

The paper deals with the influence of higher-order effects of dispersion on the femto-second transform limited pulse generation by compensating for linear chirp of self-phase modulation spectra in the dispersion-shifted fibers. It has been shown that the minimum propagation length with first-order dispersion term is 23 m, as reported earlier. If the higher-order dispersion effects are taken into consideration, this length is reduced to 11.5 m. With compensation of the first-order dispersion term, this length can be enhanced to 6.8161 × 10³ km. This length can further be improved to 6.0343 × 10⁹ km by compensation of first- and second-order dispersion terms together. The minimum pulse width and linewidth product without dispersion, with dispersion including higher-order dispersion effects, and with dispersion compensation, is found to be 0.44, 0.4418, and 0.4411, respectively.     

Maintaining single polarization and dispersion compensation with modified rectangular microstructure optical fiber

In this paper, we propose and numerically demonstrate a highly birefringent microstructure optical fiber which shows negative dispersion coefficient of about −288 to −550 ps/(nm km) covering S to L wavelength bands and −425 ps/(nm km) at the excitation wavelength 1550 nm. This proposed design successfully compensate the dispersion covering S to L communication bands ranging from 1460 to 1625 nm along with relative dispersion slope (RDS) perfectly matched to that of single mode fiber of about 0.0036 nm⁻¹. Apart from dispersion compensation, the designed MOF offers high birefringence of 2.94 × 10⁻² at 1550 nm and better compensation ratio with design simplicity due to circular air-holes in the fiber cladding.     

色散补偿光纤通信系统中孤子之间的相互作用

采用变分原理与位力定理研究了非线性光通信系统色散补偿方案中,相邻孤子之间的相互作用对孤子传输特性的影响。结果表明:在相位匹配与等幅孤子注入时,在普通单模光纤中这两个孤子先相互吸引,而后又相互排斥,显现周期性碰撞的变化规律,形成束缚孤子态,而在色散补偿光纤中传输的孤子之间不发生碰撞;对相位不匹配与等幅孤子注入,孤子之间发生分离;对相位匹配和不等幅孤子注入,在色散补偿光纤中传输的孤子,如果初始间隔φ0越小,应注入较大的初始幅值差η0,以利于孤子的传输。     

用于频域光学相干层析成像的深度分辨色散补偿方法

提出一种深度分辨的色散补偿方法,用于增强频域光学相干层析成像的纵向分辨率。将频域光学相干层析成像采集的干涉谱信号傅里叶变换到空域,获取对应不同深度的干涉谱条纹相位,通过对其进行调整实现对被测样品不同深度处的色散的精确补偿。避免传统方法中采用统一色散系数进行色散补偿所带来的过补偿与欠补偿误差,可以有效消除色散引起的频域光学相干层析成像系统点扩展函数的展宽和扭曲。模拟和实验结果表明,基于深度分辨的色散补偿方法在样品的全深度探测范围内可以达到较佳的补偿效果,可有效提高光学相干层析成像系统的纵向分辨率。     

能够补偿二阶偏振模色散的三阶段偏振模色散补偿器

简要分析了偏振相关色散对光通信系统性能的影响,提出了一种三阶段高阶偏振模色散补偿方案,从理论上分析了它同时补偿偏振相关色散和偏振主态旋转的可能性,并提出了其可能存在的两种工作方式.通过数值模拟与两阶段补偿方案进行了性能比较,其偏振模色散容限比两阶段补偿提高约17%个比特周期 关键词： 光通信 光偏振 光纤色散     

Optical Fiber Dispersion Compensation by Chirped Fiber Bragg Grating

１ＩｎｔｒｏｄｕｃｔｉｏｎＵｓｉｎｇｄｉｓｐｅｒｓｉｏｎｃｏｍｐｅｎｓａｔｉｎｇｔｅｃｈｎｉｑｕｅｓｔｏｕｐｇｒａｄｅｔｈｅｅｘｉｓｔｉｎｇｎｏｎｄｉｓｐｅｒｓｉｏｎｓｈｉｆｔｅｄｆｉｂｅｒ（ＮＤＳＦ）ｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓｙｓｔｅｍｉ...     

具有电色散补偿的10 Gb/s脉冲转换器的研制

设计并研制了带电色散补偿功能的10 Gb/s脉冲转换器。电色散补偿通过时域均衡的方法,消除光纤色散带来的码间串扰;将电色散补偿芯片纳入脉冲转换器设计中,从而提高了其传输距离。所研制的样品光发射部分采用分布反馈激光器加电吸收调制器集成光源,接收部分采用带互阻放大器的雪崩光电二极管光电探测器模块,电色散补偿芯片对光电探测器输出的码流执行色散补偿算法。对样品进行的测试结果表明该脉冲转换器背对背接收灵敏度为-24.6 dBm,经过100 km G.652光纤传输后接收灵敏度为-20.8 dBm。未加电色散补偿功能时,采用相同的光源传输距离仅为50 km。     

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     

双光栅快速扫描光学延迟线的色散补偿

光学相干层析成像(OCT)系统的纵向分辨力不仅与光源的带宽有关,而且与系统中两干涉臂间的色散匹配有关。如果色散没有得到精确匹配,将使光学相干层析成像系统的纵向分辨力达不到所预期的理论值。色散问题在超高分辨光学相干层析成像系统中尤为突出。提出了一种基于双光栅快速扫描光学延迟线(RSOD),用于光学相干层析成像系统的色散补偿。该方法中新增的光栅引入了光栅间距这一独立变量,其与常规单光栅快速扫描光学延迟线机构中的光栅离焦量一起,可使光学相干层析成像系统中的群速度色散(GVD)和三阶色散(TOD)同时得到补偿。分析了双光栅快速扫描光学延迟线的色散特性和色散调节原则,并提供了一个典型光学相干层析成像系统中的色散补偿实例。     

Requirements for Efficient Raman Amplification and Dispersion Compensation Using Microstructured Optical Fibers

Abstract

The design and performance of microstructured optical fibers (MOFs) for simultaneous dispersion compensation and Raman amplification is numerically investigated. We studied a lumped Raman amplifier designed to compensate the signal loss and dispersion introduced by a 100-km, 16-channel C-band WDM link. The impairments induced by the nonlinearities caused by the small mode area of the designed MOF are investigated and the analysis is extended to include non-ideal factors such as excess background losses, splice loss, and the geometry variations during the fabrication process. The results are discussed and compared to those obtained for conventional dispersion compensating fibers (DCFs).     

基于SOA器件的色散补偿系统

基于半导体光放大器非线性效应提出一种连续可调谐的色度色散补偿方法.利用SOA的交叉相位调制效应,对10 Gbit/s和 40 Gbit/s RZ码系统的补偿效果和补偿范围进行了仿真分析.分析结果表明,该方法在10 Gbit/s传输系统中,可以实现补偿范围为400 ps/nm的正负色散.在40 Gbit/s传输系统中,可以实现补偿范围为40 ps/nm的正负色散.在理论分析基础上,进行了10 Gbit/s传输系统下连续动态色度色散测补偿实验.实验结果表明,该方法实现了-40～60 ps/nm范围内色度色散的连续可调谐补偿.     

偏振度作为反馈信号进行偏振模色散补偿的研究

对40Gb／s光纤通信中归零码和非归零码光脉冲的偏振度随二阶偏振模色散的变化规律进行了数值模拟,结果表明由于二阶偏振模色散的影响,偏振度的变化趋势呈现出震荡性,二阶偏振模色散对归零码的偏振度要比非归零码的偏振度影响明显;同时搭建了偏振模色散补偿系统,对系统进行数值模拟和实验所得到的结果都表明,以偏振度作为反馈信号,采用粒子群优化算法作搜索算法能够有效地对归零码和非归零码系统的一阶及高阶偏振模色散进行自适应补偿。     

Optimization of NRZ Data Transmission at 10 Gbit/s over G.652 Without In-Line DFAs

Performance limits of NRZ data transmission at 10 Gbit/s over standard single mode fiber (SSMF, G.652) without the deployment of in-line erbium-doped fiber amplifiers (EDFAs) are evaluated by means of numerical simulation. The fiber system was modeled using the standard split-step Fourier algorithm for the solution of nonlinear Schroedinger equation. The effect of group velocity dispersion (GVD) compensation scheme, degree of GVD compensation of the SSMF, and input optical powers to SSMF and to the dispersion compensating fiber (DCF) have been investigated with the aim to maximize the distance between transmitter and receiver. We have found that a post-compensation scheme performs better than the pre-compensation scheme and that, by careful selection of input powers and degree of GVD compensation, it should be possible to keep the bit-error-ratio (BER) below 10 upper index = 15 for an SSMF length of 270 km.     

Optimization of NRZ Data Transmission at 10 Gbit/s over G.652 Without In-Line DFAs

Performance limits of NRZ data transmission at 10 Gbit/s over standard single mode fiber (SSMF, G.652) without the deployment of in-line erbium-doped fiber amplifiers (EDFAs) are evaluated by means of numerical simulation. The fiber system was modeled using the standard split-step Fourier algorithm for the solution of nonlinear Schroedinger equation. The effect of group velocity dispersion (GVD) compensation scheme, degree of GVD compensation of the SSMF, and input optical powers to SSMF and to the dispersion compensating fiber (DCF) have been investigated with the aim to maximize the distance between transmitter and receiver. We have found that a post-compensation scheme performs better than the pre-compensation scheme and that, by careful selection of input powers and degree of GVD compensation, it should be possible to keep the bit-error-ratio (BER) below 10 upper index = 15 for an SSMF length of 270 km.     

一种新的低非线性宽带色散补偿微结构光纤的设计

采用矢量光束传输法对空气孔包层呈正六边形分布的微结构光纤的色散和非线性特性进行了数值模拟。通过分别调节内三层空气孔的直径和包层空气孔节距,设计了一种低非线性宽带色散补偿微结构光纤。该光纤在波长1.55 μm处具有－3 235.8 ps/nm/km的大负色散,可在以1.55 μm为中心的100 nm宽带波长范围对相当于自身长度190倍的普通单模传输光纤进行宽带色散补偿(色散补偿率偏移在0.5%以内),同时该光纤可在此宽带波长范围内保持非线性系数低于5 W^-1·km^-1。