远泵放大器大功率泵浦光传输技术的实验研究

介绍了远泵放大器大功率泵浦光传输技术的实验研究,该技术应用在大跨距无中继光纤传输系统中,采用G．652光纤,构成了速率为2．5Gb／s、跨距为507km的大跨距无中继光纤传输系统。     

无中继海底光缆通信系统概述

首先对无中继海底光缆传输系统的构成进行了简要叙述，然后详细阐述了无中继系统用光纤光缆、海缆用连接器和接头、光纤放大器以及光接收机的研究现状，接着论述了其相关技术（波分复用和前向纠错）的发展，最后对无中继通信系统的发展趋势进行了分析与展望。     

数字彩色电视长波长光纤传输系统

本文介绍了数字彩电长波长(1.3μm)光纤传输系统的原理、构成及其技术指标。性能测量结果表明:模拟彩电信号经线性PCM编码,通过139.264Mb/s数字光纤系统传输,恢复模拟彩电信号后,信号质量达到了我国GB1583-79规定的短程线、中同轴国家彩电传输标准(一级国标)的指标,无中继传输距离达20.5km。若全部换用较好的国产A类多模光纤,无中继传输距离可达25km以上。     

286km 40×10 Gbit/s旁路ROPA系统的研究与应用

为了研究大容量超长跨距无中继光传输技术,采用超低损耗光纤作为传输介质,使用EFEC(增强型前向纠错)技术、Hybrid(混合)光放大器及前置旁路ROPA(远程光泵浦放大器)技术,首次实现了40×10Gbit/s OTN(光传送网)系统286km无中继超长跨距传输,系统连续运行24h无误码。该应用成果为衡量超长跨距大容量光纤传输ROPA系统的性能指标和应用标准等提供了依据。     

取代石英玻璃的1万公里无中继传输的氟化物光纤试制成功

从透光率计算氟化物玻璃的光损耗来看,氟化物损耗的理论极限值竟达石英玻璃的百分之一以下,即每公里0.001分贝。目前,石英玻璃光纤100公里无中继传输成功的实验实例已有报导,根据计算氟化物光纤有可能获得1万公里无中继传输,认为对海底光缆特别有效。将来有可能生产出日美之间1万公里无中继传输用的光纤。作为光纤材料,在期待低损耗的同时,光纤加工时     

胜利油田有线电视光纤传输系统

该系统为国有企业中有线电视光纤传输的大型系统，其中63km无中继和93km模拟传输为国内的第一个实用系统。     

光纤技术的进展速度如何?

最近几年来,光纤系统朝着码速高、中继间距大的方向稳步发展,在一些研究报告中和市场上均可目睹这种趋势。ATT贝尔实验室的研究人员在85年光纤通信会议上报导,他们在无中继117km光纤上传输了4Gb/s码速的信号。在85年欧洲光通信会议上,贝尔实验室小组介绍了在中长度30km光纤上传输8 Gb/s码速信号的情况。在86年亚特兰大光纤会议上,贝尔实验室介绍了在无中继68.3km光纤上传输8Gb/s码速     

NTT设计400Mb/s1.5μm系统

日本电报电话公司(NTT)在原有的F-400光纤系统的基础上设计出传输波长为1.5μm的新型通信系统,原系统传输波长为1.3μm,它是纵贯日本本土的远距离电话通信系统的主干线。该公司为了增加陆上系统的中继距离,并避免水下系统使用中继器,正在努力开发更长波长的光纤系统。新系统采用的是1.5μm分布反馈型激光二极管,常规1.3μm零色散单模光纤和铟镓砷雪崩光电二极管。该系统在陆上的无中继传输距离为80公里,用于海底通信时无中继传输距离达120公里。这就可以在陆上     

139.264Mb/s数字彩电光纤传输系统

实验表明,经四次群数字光纤系统传输的八位线性PCM编码彩色电视信号,能满足广播电视质量的要求,彩电质量达到了我国GB1583-79规定的短程线、中同轴国家彩电标准(一级国标)的指标,无中继传输距离达20.5km。若换用较好的光纤,不论损耗或带宽限制,无中继传输距离都可达25km以上。该系统除A/D、D/A集成组件外,其余全部都是国产器件。     

400Mbit/s光发射机模型

一、引言根据国际上光纤通信的发展趋势,我们对400 Mbit/s单模光纤传输系统进行了研究,并全部采用国产器件制造出了系统性能样机,从而在国内首次成功地实现了1.3μm波长、400 Mbit/s、30km无中继单模光纤的传输。本系统采用单模激光器(波长为1.3μm)作为系统光源,Ge-APD作探测器;无中继光纤长度为30 km;接收机灵敏度为-32 dBm(BER<10~(-9))。本文主要介绍光发射机部分的性能、特点和电路结构。     

海底光缆通信系统的最新进展

回顾了海底光缆通信系统的发展历程,介绍了海底光缆系统技术的最新进展,特别讨论了偏振复用相干接收无中继传输试验系统和偏振复用副载波调制光正交频分复用（SCM-C0-0FDM）相干检测WDM系统的构成和实现原理。     

Design and characterization of dispersion compensating fiber basedon the LP01 mode

The practical implementation of erbium-doped fiber amplifiers with gain at 1.55 μm allows long unrepeatered transmission distances. However, in order to realize high data rates over these distances with already installed standard single mode fiber, techniques must be found to overcome the pulse spreading due to the positive chromatic dispersion of the transmission fiber in this window, we review a compensation technique based on propagating the signals through a specially designed fiber with large negative dispersion for the LP₀₁ mode, thereby ending up with zero net pulse spreading. The basis of the concept are discussed and a key figure of merit for dispersion compensating devices is defined. The design and optimization of dispersion compensating (DC) fiber is described with special attention to practical concerns including packaging and manufacturability. We describe experimental fabrication results of DC fiber, results of using the fiber to make compact dispersion compensating modules, and the outcome of recent systems experiments incorporating the fiber     

利用啁啾光纤光栅的色度色散补偿方案的研究

本文针对高速率光传输系统中的色度色散问题,利用啁啾光纤光栅,设计了后置补偿、前置补偿和混合补偿三种方案并实现了320k。的G．652光纤单信道40Gbit/s的无中继传输,仿真实验结果表明：较之后置补偿和前置补偿,混合补偿具有最好的色散补偿性能。     

Bidirectional unrepeatered 43 Gb/s WDM transmission with C/L band-separated Raman amplification

A novel wavelength arrangement using C- and L-band-separated Raman preamplification is proposed for application to bidirectional unrepeatered transmission systems operating with multiple 43 Gb/s channels. The proposed wavelength allocation makes it possible to greatly mitigate Raman gain depletion by the counter-propagating signals. The authors have achieved bidirectional unrepeatered transmission of 32 /spl times/ 43 Gb/s channels (= 1.28 Tb/s) over 200 km with Raman preamplifiers using the proposed technique. They found that the system performance of bidirectional transmission with C/L band-separated Raman preamplification is degraded by nonlinear interactions between the high power Raman pump lights and the WDM signals. The root cause can be described in terms of nondegenerate four-wave mixing induced by beating between the WDM signals and two longitudinal modes of the Raman pump light. A solution avoiding ND-FWM was demonstrated in a 32 /spl times/ 43 Gb/s transmission experiment.     

Reach Extension of a DPSK Optical Link Using an Optical Filter Demodulator and MLSE Receiver

We have proposed a novel scheme based on chirped fiber Bragg grating (CFBG) as a narrowband optical filter demodulator and a maximum likelihood sequence estimation (MLSE) receiver to attain an enhanced unrepeatered reach in a nonreturn-to-zero differential phase-shift-keying (NRZ-DPSK) transmission link. An extended reach up to 500 km with only 2-dB optical signal-to-noise ratio penalty is found feasible for a 10.7-Gb/s NRZ-DPSK link with the CFBG-MLSE combination.      

High-capacity 1.3 ?m unrepeatered optical fibre transmission system trials for submarine applications

A series of high-capacity optical transmission system experiments at 1.3 ?m wavelength are reported. Margins greater than 2 dB were observed at 144 Mbit/s over 93 km and at 750 Mbit/s over 65 km, thus demonstrating the practicality of unrepeatered optical systems using commercially available components.     

Unrepeatered submarine systems – market trends, applications and technologies

The current situation in the submarine fibre optics market is described. The submarine business is suffering from the same malaiseas the rest of the telecommunications industry. Some reasons and present trends are outlined in this paper. Unrepeateredsubmarine systems are not so seriously affected by the downturn as the repeatered sector, and offer fresh opportunities for newsuppliers previously excluded from the submarine market. In this case, collaborations with other companies are a preconditionsince customers expect complete, turnkey projects. Typical applications of unrepeatered systems are presented and theeconomics of unrepeatered versus repeatered systems are compared, showing the benefits of unrepeatered systems. The successof systems based on technologically enabling factors, such as FEC schemes, fibre types, and the compensation of nonlineareffects, are discussed together with future technological developments. Finally, a successful example of the deployment of anunrepeatered submarine system (ARCOS 1) is presented.     

High Bit Rate OTDM-Transmission on Standard Fibre

In this paper we describe experimental and numerical studies on high bit rate, single span transmission system over a length of 160 km without amplifiers in the link (unrepeatered). From these studies we revealed that the tolerance of the residual dispersion is very restrictive. Proper dispersion management and PMD compensation techniques are important topics in these and future systems.