长途高速骨干网光传输系统的优化设计

为了改善长途高速骨干网光传输系统的传输性能,对其系统器件进行了优化配置,主要包括提出一种新的光放大器的配置方案,在光传送单元（OTU）中引入FEC技术。以便实现在确保低成本的条件下实现高效、高质量传输要求的目的。     

分布式FRA在WDM光传输系统中的作用

本文对分布式光纤喇曼放大器（FRA）利用功率耦合微分方程进行了数值计算，分析其分布放大特性，并结合对光纤通信系统容限及性能的计算讨论了利用FRA的分布放大特性降低WDM信号非线性，提高信噪比从而提高系统性能的可行性。此外指出了其在实际应用中的分布放大和频带利用等方面的局限性。     

WDM光线路自动倒换保护技术

在总结WDM自动保护技术及目前存在问题的基础上，介绍了WDM光线路自动倒换保护技术原理及其工程应用方案，同时提出了在工程应用时应注意的一些问题。     

Technology Requirements for Optical Fiber Submarine Systems

The development of optical fiber technology has advanced to the point where optical submarine systems can be contemplated. However, considerable attention must be paid to developing and then proving the acceptability of the several technologies new to submarine systems. Areas of particular significance include fiber reliability and cabling, performance and reliability of electrooptic components, and the establishment of reliable and cost-effective electronic circuitry. The development of first-generation systems is well under way and the possibility of more advanced systems exists, as new techniques become established.     

WDM传输系统使用的光纤放大器

ＷＤＭ技术的开发已经成为通信领域的热点，而光纤放大器是ＷＤＭ系统的关键器件，本文介绍了ＷＤＭ传输系统对其线路中使用的光纤放大器的各项技术指标要求，同时还介绍了几种最近几年来研制的适合于ＷＤＭ传输系统的光纤放大器。     

波分复用系统和光孤子通信系统中的光放大器

本文首先介绍了光放大器的分类,然后针对波分复用系统和光弧子系统对光放大器不同特性的要求,讨论了适合于这两个系统的光放大器,并分析了各种可行的改进措施。     

Optimization of Single-Sideband DCS-RZ Format for Long-Haul 43-Gb/s/channel Ultradense WDM Systems

The optimization of the single-sideband (SSB) duobinary carrier-suppressed (DCS) return-to-zero (RZ) format for long-haul ultradense wavelength-division multiplexing (UDWDM) systems with a 43-Gb/s/channel and a channel spacing of 50 GHz is investigated numerically. It is shown that the optimized SSB-DCS-RZ format with an electrical transmitter bandwidth of 0.35 of the bit rate has about 1 dB of Q-factor improvement relative to the conventional SSB-DCS-RZ format (an electrical transmitter bandwidth of 0.25 of the bit rate) due to the reduction of noise bandwidth, smaller linear crosstalk, and better tolerance to the intra-channel fiber nonlinear effects. No substantially different UDWDM system performance is observed when varying the duty cycle of the DCS-RZ signal with optimized SSB filters settings. The UDWDM transmission performance of SSB-DCS-RZ formats is compared with the bandwidth-limited (BL)-duobinary formats. It is shown that generally, the SSB-DCS-RZ formats have poorer Q-factor and tolerance to the total residual dispersion but much higher tolerance to the in-line dispersion compensation and intra-channel nonlinear effects than the BL-duobinary formats     

海底光缆传输系统简介

随着新技术和新设备的不断出现，为未来的海底光缆传输系统的发展提供了广阔的前景。本文根据ＣＣＩＴＴ建议Ｇ．９７１、Ｇ．９７２和Ｇ．９７４，介绍海底光缆传输系统的基本组成和特性，然后讨论光纤放大器的基本原理及其在海底光缆传输系统中的应用。     

Design Considerations for Long-Haul Lightwave Systems

The following design considerations for long-haul lightwave systems are reviewed: outage and error rate requirements, terminal architecture, regenerator span design and performance specification, capacity upgrade alternatives, and broad-gauge economic factors.     

用于光纤传输系统的半导体激光放大器

本文主要介绍用于光纤传输系统的行波半导体激光放大器(TWSLA)。首先描述 TWSLA 的激光器刻面抗反射(AR)涂层的特性,然后描述半导体激光放大器(SLA)的重要特性,如小信号增益、信号增益饱和及噪声特性,最后讨论了 TWSLA 的结构设计。     

波分复用WDM技术与超长距离传输

从WDM技术特点、RAMAN放大器、超强FEC ,色散补偿的方面讨论最新的发展趋势和关键性技术     

A Feedback Receive Amplifier for Optical Transmission Systems

We consider the design and implementation of a lownoise feedback receive amplifier for use in optical communication systems. The feedback amplifier configuration is advantageous in that it offers a wide bandwidth with good signal to noise ratio.     

A Study of the Key Techniques of High-Speed Optical Time Division Multiplexing Systems

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Stratified Sampling Monte Carlo Algorithm for Efficient BER Estimation in Long-Haul Optical Transmission Systems

We propose an efficient stratified sampling (SS) algorithm for estimating the bit error rate (BER) of a digital communication system. Our algorithm efficiently exploits the observations of an approximate, but usually fast, model of the system under investigation to drive a clever Monte Carlo (MC) estimation based on SS. The proposed method is faster than standard MC even at BER in the range $10^{-3}$ to $10^{-5}$ . Moreover, it is possible to evaluate the estimated standard deviation of the measured BER, such as in an MC simulation, so that it is possible to associate a confidence to the results. We test the algorithm both in a simple optical system distorted by group velocity dispersion (GVD) and in more complex differential quadrature phase shift keying (DQPSK) systems. In the last case, we measured computational savings up to 70% compared with standard MC.      

A High-Speed Optical Data Highway for Industrial Control Systems

Recent application of distributed control systems to large-and medium-scale industrial plants requires effective and high-speed communication among the control devices each other to ensure high-performance operation.     

Upgrading WDM Submarine Systems to 40-Gbit/s Channel Bitrate

The introduction of wavelength division multiplexing (WDM) has triggered a tremendous capacity growth in submarine systems, both by the increase of the number of WDM channels and by the increase of the channel bitrate. Starting from 2.5 Gbit/s in the mid-1990s, the bitrate was upgraded to 10 Gbit/s by the end of the century in commercial products. The next generation of submarine systems will likely be based on a 40-Gbit/s bitrate. However, transmissions at a 40-Gbit/s rate are more challenging than transmissions at 10 Gbit/s. The goal of this paper is to provide an overview of the technologies which could be required or used in next-generation submarine systems. In the first part of this paper, an overview of the history of submarine links is provided. Then the technologies used in current N /spl times/ 10 Gbit/s systems are described. Eventually, the challenges to overcome are discussed, whether they concern the type of fiber, the type of optical amplifier, or the nature of the modulation format.     

A Consideration of an Optical Coupler for Optical Submarine Transmission Laser Redundancy Systems

Theoretical and experimental results are described for a new optical coupler which consists of two laser diodes, two GRIN spherical rod lenses, a polarizing filter, and a single-mode fiber, and which employs laser diode polarization characteristics for an optical submarine transmission laser redundancy system. This optical coupler has two channels at 1.3 μm wavelength. Optical coupler loss values, which include coupling loss, polarization loss, and assembly loss, are 4.9 dB for one laser diode and 5.2 dB for another laser diode. Such loss values are almost the same as the conventional laser diode module loss for a single-mode fiber. This paper describes in detail a laser redundancy system in an optical submarine transmission system, structure and characteristics of an optical coupler, and experimental results on a high bit rate long-haul transmission system using the proposed optical coupler.     

光学和光电子系统用的微机械加工技术

回顾了微机械加工技术的最新进展, 介绍了自由空间微型光学试验平台和光预对准的概念以及微机械加工的光学器件实例。     

Calculation of Achievable Information Rates of Long-Haul Optical Transmission Systems Using Instanton Approach

A method for estimation of achievable information rates of high-speed optical transmission systems is proposed. This method consists of two steps: 1) approximating probability density functions for energy of pulses, which is done by the instanton approach, and 2) estimating achievable information rates by applying a method originally proposed by Arnold and Pfitser. Numerical results for a specific optical transmission system (submarine system at transmission rate 40 Gb/s) are reported     

光通信中波分复用器件的实现技术

介绍了宽带光通信中最关键的器件－波分复用器件的各种实现技术，包括级联型的介质薄膜滤波型、光纤布拉格光栅型、马赫－曾德干涉型和色散型的体光栅型、平面集成型。文章对这些实现技术的特点进行了详细的分析和比较，最后给出了结论和展望。