一种新型超低损耗大有效面光纤的技术研究

采用双包层的波导结构结合纯二氧化硅芯的技术方案,通过包层氟掺杂的设计与芯/包层之间粘度匹配的优化,实现了超低损耗大有效面积ULA-130型G.654.E光纤的制造,然后利用自行搭建的光纤非线性系数测量系统和自主设计的光纤宏弯损耗松绕设备,结合现有技术对ULA-130光纤的各项性能技术指标进行了研究。该光纤在1 550 nm波长的衰减系数为0.159 dB/km,有效面积为133 μm²,非线性系数为1.67×10^-10W^-1。理论计算与技术研究结果表明,该光纤具有优异的衰减系数和非线性性能,适用于大容量、高速率和长距离光通信骨干网传输系统,相对于常规的 G.652.D 光纤,可以显著改善系统的光信噪比,提升系统的传输性能。     

Optical nets brace for even heavier traffic

Thanks to that Internet, backbone traffic has been increasing at a compound annual growth rate of more than 100 percent for several years. The owners of the backbone infrastructure, which is almost entirely fiber-based, are therefore eagerly embracing technologies that add to the capacity of fiber-optic systems without adding mountains of new optical cable. Having sufficient backbone capacity doesn't mean that everyone gets a high-speed connection to the Internet. It simply means that huge quantities of data can be transported between and among certain locations. There is still the problem of the last mile-the connection between the service provider and the end-user. The economics of using fibre for the last mile are open to question. One alternative approach to the last mile is fiberless optics-transmitting unguided laser beams through the air. Yet to be commercially deployed, the technology promises both high transmission speeds and fast provisioning (installation). The author describes this technology as well as ways to increase the capacity of optical fibres using WDM or raising the bit rate of each TDM data stream     

Effect of fibre dispersion on four-wave mixing in multichannel coherent optical transmission system

Severe bit error rate degradations and strong error rate floors caused by fibre four-wave mixing (FWM) in a high launch power, seven channel, coherent optical transmission system are reported. The critical influence of fibre chronic dispersion is highlighted, with a negligible penalty after transmission over conventional step index fibre, even for a launch power of +17 dBm. Several orders of FWM products are visible in the optical spectra for dispersion shifted fibre.<>     

2.4 Gbit/s 100 km penalty-free conventional fibre transmission experiments using GaInAsP electroabsorption modulator

The superior characteristics of a semiconductor modulator for a multi-Gbit/s and long-haul fibre transmission are confirmed for the first time. A 2.4 Gbit/s over 100 km conventional single-mode fibre transmission has been successfully achieved by using a GaInAsP electroabsorption modulator. No power penalty was observed even under 1700 ps/nm chromatic fibre dispersion.<>     

Optical-transmission experiment at 400 mb/s using a graded-index fibre

An optical-transmission error-rate experiment is described in which a graded-index fibre up to 5 km long is used as a transmission medium. It is shown that impairments in the transmission are mainly determined by the total frequency response of the transmission medium, including the fibre and its connection.     

Optical amplifiers for video distribution

The promise of a broadband fibre communications network has attracted the interest of CATV and Telco concerns. Various networks and topologies have been discussed. Cost is a drawback in some of the proposed networks, particularly those networks which require switching. This paper discusses a low cost broadcast tree and branch network which uses optical amplifiers to extend the network penetration. Recent work in the development of optical amplifiers suggests that the Erbium fibre amplifier may be compatible with VSB-AM. The characteristics of such an amplifier will be discussed. This scenario allows an orderly transition from the present-day AM backbone system to the tree and branch fibre architecture. Once the broadband fibre plant is in place new services can be implemented that exploit the broadband nature of fibre.     

光纤传输在计算机局部网络中的应用前景

本文从光纤传输在计算机局部网络中的结构、制式和优点着手,展望了在计算机局部网络中采用光纤传输的应用前景。     

长周期莫尔光栅的理论研究

长周期光纤光栅作为一种损耗型的带阻滤波器，在光纤通信和光纤传感器领域有着广泛的应用。结合长周期光纤光栅的传输特性，利用传输矩阵法对多种长周期莫尔光栅的透射谱进行了理论模拟。分析结果表明，莫尔光栅技术在制作高性能的相移长周期光栅和变迹长周期光栅上有着很好的应用前景。     

Soliton transmission over more than 90 km using distributederbium-doped fibres

The transmission of 11.5 ps solitons over 93.4 km of distributed erbium-doped fibre is reported. By inserting a 29.3 km long midsection singlemode fibre instead of 32.5 km of erbium-doped fibre, the signal excursions are lowered, and 9.0 ps solitons are transmitted over 90.2 km     

Use of optical `feedthrough' transceivers for bidirectionaltransmission systems

Optical fibre is rapidly becoming the preferred transmission medium for both telecommunication and data communication networks. However, the deployment of optical systems in high-density local-area networks can be enhanced by the use of low-cost architectures and components. Bidirectional networks, in which send and receive signals are carried simultaneously on a single fibre, offer the possibility of reduced fibre costs. However, to fully exploit this technique it will be necessary to employ transceiver modules consisting of an optical transmitter and receiver colocated in the same package. The authors describe a low-cost optical transceiver module that is capable of supporting full duplex transmission on singlemode optical fibre     

Suppression of SBS by discontinuous Brillouin frequency shifted fibre in CPFSK coherent lightwave system with booster amplifier

The impact of a compound fibre exhibiting discontinuous Brillouin shifts on stimulated Brillouin scattering (SBS) in a 2.5 Gbit/s CPFSK transmission system consisting of an optical booster amplifier and a nondispersion shifted transmission fibre is described. The power penalty due to SBS is almost completely eliminated by the novel compound fibre which is constructed with four short lengths of nondispersion shifted fibre joined end to end.<>     

Transmission loss in low grade SiCl4 v.a.d. fibres

The transmission loss of v.a.d. fibres made from various grade raw materials has been studied. It has been found that low loss spectra are obtained in v.a.d. fibre fabricated from the raw material of low grade silicon tetrachloride (99.17%). The transmission loss of the fibre is 0.60 dB/km at 1.55 ?m.     

时间触发光纤通道节点设计与实现

综合化航空电子系统对总线网络的传输速率和确定性提出了较高要求。针对普通光纤通道总线存在确定性差的问题,提出了一种时间触发光纤通道总线的设计与实现方案,采用主从方式实现网络时间同步,以及多缓存时间触发传输结构。详细阐述了节点的现场可编程门阵列逻辑设计实现方案,并在样机平台上进行了实物测试与验证。所提出的基于光纤通道的时间触发传输方案仅需对节点协议进行适应性修改,可应用于综合化的航空电子系统。     

色散控制孤子系统的应用设计研究

对色散控制孤子(DMS)系统的设计展开研究,首次通过DMS系统的传输理论研究系统参数受限度,确定DMS传输系统的参数以及系统设计步骤,然后研究将DMS传输系统应用于一段实际的干线网络。作为优化设计DMS系统传输参数的例子,改建后的干线网的传输特性和眼图性能良好,基本上能得到理想的结果。为色散管理孤子方案应用于实际系统提供有价值的参考,为升级传统光纤线路,实现高速大容量传输提供有益的参考。     

色散控制孤子系统的设计方法研究

为色散控制孤子(DMS)系统的设计提供方法和步骤.通过研究DMS系统的传输理论,确定所研究的系统参数受限度,然后给出了DMS传输系统设计的步骤.作为优化设计DMS系统传输参数的例子,将DMS传输系统应用于一段实际的干线网络.研究表明,应用该方法,DMS能传输800 km改建后的干线网,而保持良好的传输特性和眼图性能.为色散管理孤子方案应用于实际系统而提供有价值的参考,为实现高速大容量传输提供有益的探索.     

Direct coupling from a GaAs laser into a single-mode fibre

Ways of coupling directly to a monomode fibre by neutralising the end reflection from the laser and then using the face of the fibre core as a cavity mirror are proposed. The condition is derived for the optimum transfer of power from the laser resonator to the fibre transmission line.     

Wide-stopband chirped fibre moire grating transmission filters

Efficient, wide-stopband fibre transmission filters with single narrow transmission bands produced using multiply exposed chirped fibre grating resonators are reported. Tailored combinations of these structures with additional chirped gratings have achieved single passband transmission with an effective finesse of 48. This demonstrates the feasibility of fabricating all-fibre transmission filters with arbitrary passband/stopband combinations     

中国联通长途骨干网上的DWDM技术

本文通过介绍2000年中国联通途径传输骨干网,讨论DWDM技术在中国联通长途传输骨干的应用情况,并展望未来的发展设想。     

Graded-index-type crystalline fibre for IR light transmission

A new method for making a graded-index-type crystalline fibre is proposed. A fibre for IR light transmission with crystalline claddings was desired for improving the reliability of the crystallinc fibre and for avoiding any excess loss at the core surface. A fibre with the core-cladding structure was made by complex extrusion with KRS-5 as the core and KRS-6 as the cladding. Obtaining a smooth core-cladding interface was very difficult. This problem was overcome by a diffusion of composite ions by annealing after the extrusion. The fibre has a concentration distribution that can be accounted for by a GI fibre. The transmission loss of the CO2 laser is 0.2 dB/m with a launching NA of 0.05.