超高速传输与色散管理技术

综述了超高速传输的各种限制因素；分析了各种光纤的超高速传输特性；提出标准单模光纤加色散补偿技术是利用已敷设光纤改造升级的一种较好途径，色散位移光纤适合于单信道长途传输，而非零色散位移光纤既可满足当前需要，又可在将来利用波分复用（ＷＤＭ）技术升级，是新建长途线路的一种较理想方案。     

色散管理光传输线路及光纤

波分复用（WDM）和高比特速率时分复用（TDM）作为满足传输容量增长需求的技术得到了迅速发展。在此之前,利用C带（在1550nm附近）通过2.5Gb/s和10Gb/sWDM已实现了容量的扩大,目前正在加速对L带（在1600nm附近）的研究,以进一步扩大容量。随着电信号处理极限40Gb/s速度的实现,100Gb/s速度的光时分复用逐渐获得应用。在这种高密度、高比和持速率WDM传输中,光纤中存在的非性现象会降低传输质量,由此提高了抑制非线性技术的重要性,尤其是在WDM传输系统四波混合（FWM）情况下。同时还明显存在着由色散引起的信号失真问题,因此抑制累积色散的技术同样必不可少。此外,在宽带波长范围内还需要可以进行复杂色散管理的传输线路,它可以由新型光纤组成。     

一种用于高速DWDM系统的色散补偿新方案

在高速光纤通信系统、特别是单信道速率为10Gb／s以上的系统中,色散补偿是提高信噪比(SNR)、改善系统性能的必要手段。从实用的角度,提出了一种适用于单通道40Gb／s、80个通道的高速密集波分复用(DWDM)系统的色散补偿方案,即采用全拉曼放大,将色散补偿光纤进行合理的配置,达到色散补偿的目的。仿真验证表明,该方案可实现在普通单模光纤中跨距500km的传输。     

色散管理孤子

分析了色散管理孤子（DMS）的基本原理和特性，并通过数值计算对DMS的传输进行了模拟，证实了DMS具有诸多比普通孤子更为优越的性能。同时也对密集色散管理孤子（DDMS）做了介绍，并在数值计算的基础上将其与类线性和普通DMS传输作了比较，发现DDMS在高速窄脉冲情况下有更好的传输特性。     

光纤色散和非线性对DWDM系统的影响及其消除

围绕光纤色散和非线性效应对DWDM系统传输限制的问题进行了深入的讨论。提出消除限制DWDM传输的有效方法。     

WDM传输系统中的高阶色散管理方法

在长距离波分复用(WDM)光纤通信系统中，色散和非线性是影响系统性能的主要因素，为减小由此引起的四波混频(FWM)窜扰和信号波形失真，本文详细分析了传输线路局部参数对系统性能的影响，提出了在不同DWDM系统中，高阶色散管理线路的最佳参数配置方法，用以增加系统传输容量，提高系统性能。     

色散补偿光纤应用技术的探讨

在分析色散补偿光纤（ＤＣＦ）应用原理的基础上，对ＤＣＦ特性的评价，ＤＣＦ和常规单模光纤连接损耗的降低，ＤＣＦ和掺饵光纤放大器（ＥＤＦＡ）与常规单模光纤线路的连接方式以及色散补偿传输系统中继距离的估算等应用技术进行了探讨，并提出了一些新的看法和建议。     

光网络用色散补偿器的市场前景

１引言随着密集波分复用（DWDM）技术的提高，远距离光缆已能传输多信道，覆盖很宽光谱范围的多个波长（现在常用为３２个，商用为１２８个，２０００年已达２５６个波长），并能传输很高的数据率（现在为１５５Mbit／s～１０Gbit／s）。当DWDM使得同一根光纤可插入更多的波长（通道），并在这些波长上使传输速率达到更高时，载波光纤即面临色散问题。光纤特性对通过光纤传输的信号脉冲有很大的影响，尤其是在远距离网络中影响更大。其中较显著的影响是色散，而色散的大小与数据率和波长相关（偏振色散会加大这种影响）。所以必须沿着光…     

用于新颖高速网的1550nm光纤

本文介绍用于提高长途通信网的传输容量和传输距离的１５５０ｎｍ色散位移光纤的制作方法及其性能。     

康宁公司的MetroCor光纤

美国康宁公司的研究人员通过研究证明 ,采用直接调制激光器 (DML )可以在 10 0 km长的该公司的 Metro Cor光纤上传输 10 Gb/s的信号 ,而无需价格昂贵的色散补偿。DML是都市网系统理想的发射机 ,因为它们体积小、价格便宜 ,而且激励电压低 ,输出功率大。但是 ,以前的实验一直受到这种激光器正色散的限制 ,因为信号传输距离仅为 10 km左右时 ,就因色散而降质。“Metro Cor光纤在其整个可用光纤带宽范围内都具有负色散”,康宁公司的 Ioannis Tomkos解释说。“激光器的正色散与光纤的负色散相互作用使光脉冲压缩 ,实现长距离传输而无需任…     

A study on the relationship between DWDM transmission performance and chromatic dispersion

In this letter, we numerically study the relationship between 40-Gb/s-based dense wavelength-division-multiplexing (DWDM) transmission performance and chromatic dispersion in two different transmission lines. We show that the optimum chromatic dispersion region for improving the DWDM transmission performance varies with the type of transmission line. We also show that a hybrid transmission line has a greater potential to resist any change in the dispersion slope compensation characteristics than a single fiber transmission line with a dispersion compensation fiber module. Finally, we show that chromatic dispersion of more than 12 ps/nm/km in a hybrid transmission line is optimum for a 40-Gb/s-based DWDM transmission system by taking the design of a dispersion compensating fiber into account.     

Tunable silicon etalon for simultaneous spectral filtering andwavelength monitoring of a DWDM transmitter

A temperature-tunable Fabry-Perot filter made of silicon has been developed and applied for simultaneous spectral filtering and wavelength monitoring of a directly modulated DFB laser. This novel device decreases the dispersion penalty of a cost-effective dense wavelength-division-multiplexing (DWDM) transmitter in a long-haul transmission link. Moreover, it allows the operating wavelength of the transmitter to be accurately monitored in real time     

Nonlinear distortion reduction by SPM and XPM chirp cancellation in NZ-DSF based DWDM transmissions

We propose a chirp cancellation method reducing nonlinear distortion in NZ-DSF based long-haul DWDM transmission systems in which SPM and XPM-induced chirps are canceling each other. The polarity and the amount of the XPM-induced chirp are controlled by varying the relative time shift between pulses on neighboring channels and the launching channel power. Simulation results indicate that the proposed method can provide an improved performance in terms of Q-factor in long-haul DWDM transmissions.     

光子晶体光纤的传输性能

文章首先提出了石英玻璃单模光纤在高速率、大容量和远距离光纤通信中应用时存在的问题,然后在介绍光子晶体光纤的结构特点、导光机理的基础上,简要地阐述了光子晶体光纤的研究历史和最新研究成果;最后综述了光子晶体光纤的衰减、色散和非线性效应等传输性能.     

新一代大保实光纤及其主要性能指标

从理论上对色散和非线性效应的影响进行了简要分析，介绍了一种既能控制色散，又能有效抑制非线性效应，而且具有低PMD值的适合于大容量和超长中继距离的DWDM系统的非零色散位移单模光纤－大保实。     

WDM field trials of 43-Gb/s/channel transport system for optical transport network

This paper describes recent technical challenges and the progress toward the realization of the optical transport network (OTN) based on 43 Gb/s channel. We describe the new digital frame format "OTU3: Optical Channel Transport Unit 3," which is standardized in ITU-T for OTN, for the enhancement of the network management capability in the OTN based on 43-Gb/s channels. We first proposed 43-Gb/s/ch dense wavelength-division multiplexing (DWDM) dispersion-managed transmission system using carrier-suppressed return-to-zero (CS-RZ) format that has several attractive features; it advances the evolution of OTN into 100 GHz-spaced long-haul DWDM transport networks. The first wavelength-division multiplexing (WDM) field trials confirmed the superiority of CS-RZ format in the DWDM transmission performance for the first time. The first 1 Tb/s (25 /spl times/ 43 Gb/s) WDM field trial confirmed the excellent network management capability of OTU3 in future data-centric OTN using the newly developed 43-Gb/s OTN line-terminal prototype.     

可调谐激光器技术及其在DWDM系统的应用

大容量、长距离DWDM传输系统及动态波长交换DWDM光网络对保护方式、波长分配、波长备份成本的要求,使可调谐激光器变得十分重要。讨论了常用可调谐激光器的技术原理和水平,概要说明了可调谐激光器的市场前景,介绍了可调谐激光器在DWDM系统中的部分应用。     

The Influence of Directly Modulated DFB Lasers on the Transmission Performance of Carrier-Suppressed Single-Sideband Optical OFDM Signals Over IMDD SMF Systems

The transmission performance of carrier-suppressed, single-sideband (SSB), optical orthogonal frequency division multiplexing (OOFDM) signals is investigated numerically in intensity-modulation and direct-detection (IMDD) single-mode fiber (SMF) systems using directly modulated DFB lasers (DMLs), with special attention being given to the impact of DMLs on the system performance. The dependence of the optimum carrier suppression ratio is identified on DML operating condition and optical input power. It is shown that, for DML-based optical amplification-free metropolitan systems, 30 Gb/s over 80-km SMF transmission is achievable, which doubles the performance obtained by using double-sideband (DSB) OOFDM signals without carrier suppression, and that 10 Gb/s over 1200-km SMF transmission is also feasible for DML-based long-haul systems consisting of optical amplifiers. The results indicate that the SSB technique with an optimum carrier suppression ratio reduces considerably the DML-induced nonlinear effect, and leads to decreased susceptibility of the aforementioned transmission performance to variations in DML operating condition and optical input power.      

Long-haul WDM transmission using higher order fiber dispersionmanagement

We propose a fiber dispersion management scheme for large-capacity long-haul wavelength division multiplexing (WDM) transmission systems that considers not only second- but also third-order dispersion characteristics using transmission fibers with opposite dispersion signs. It eliminates the waveform distortion of WDM signals that originates from the existence of third-order dispersion, which is a constraint placed on WDM capacity in conventional dispersion management, while reducing the interchannel interaction caused by the interplay of fiber nonlinearity and second-order dispersion. Design concept of the scheme is discussed to show the feasibility of using actual fiber parameters. An experimental investigation on transmission performance regarding the signal pulse format, nonreturn-to-zero (NRZ) and return-to-zero (RZ), and interchannel interaction caused by four-wave mixing (FWM) and cross-phase modulation (XPM) is described for optimizing WDM system performance. It is experimentally shown that RZ pulse transmission is possible without significant spectral broadening over a wide wavelength range in dispersion managed fiber spans. Using these results together with a wideband optical amplifier gain-bandwidth management technique, yields long-distance WDM transmission with the capacity of 25×10 Gb/s over 9288 km     

Performance optimization of RZ data format in WDM systems using tunable pulse-width management at the transmitter

Tunable pulse-width management is one of the efficient methods to enhance the robustness of return-to-zero (RZ) data formats for long-haul transmission systems. We demonstrate both single channel and 4 /spl times/ 10-Gb/s wavelength-division-multiplexed performance optimization using tunable pulse-width management. Pure RZ single with tunable pulse-width is generated by changing the driving voltages on a phase modulator and the dispersion values of a tunable dispersion element simultaneously according to our simulation results. Varying the pulse width from 50 to 10 ps at the transmitter can almost double the transmission distance with 4% variation in the residual link dispersion.