Structural design for nonmetallic optical fiber cables made of high-modulus and low linear-expansion coefficient polymer tubes

This paper describes a design method for a simple structure nonmetallic optical fiber cable, consisting of stranded loose tubes which are made from a high Young's modulus and low linear-expansion coefficient new polymer. First, the Young's modulus and stranding pitch of the tube unit to effectively bear all laying tension have become obvious from mechanical investigation. The allowable region between the pitch and optical fiber excess length also became obvious. In the allowable region, no additional loss due to tube characteristics was observed in the wide range ofpm 60degC. Moreover, it is shown that good performance of the cable using the new polymers is not attained using conventional cable materials.     

Design of Deep-Sea Submarine Optical Fiber Cable

On designing optical fiber cable, it is necessary to deal with optical fiber weakness, such as small breaking elongation compared to metal materials and excess loss under both lateral and hydraulic pressure. This paper presents a structural design method for the submarine optical fiber unit and cable based on the study of both lateral and hydraulic pressure characteristics. This paper also clarifies that the fiber proof test level has been determined for new cables to be applied in sea areas 8000 m in depth.     

新型高压光纤复合电缆防水牵引头的设计

对常规电缆牵引头存在的缺陷进行了分析,详细介绍了研制的新型高压光纤复合电缆防水牵引头的结构及其安装方法,并对该新型电缆防水牵引头进行了拉力及防水试验。该新型电缆防水牵引头已在用户现场施工应用时起到了重要作用。     

The Blown Fiber Cable

A radically new approach to optical fiber cable design and installation is described. Packages containing a number of optical fibers were drawn into preinstalled empty bores (tubes) using the viscous drag of air. The drag force acting on the fiber package is distributed along its length, which makes it possible to introduce fibers into complicated routes, with low strain. In this paper, we will concentrate mainly on the design of the fiber package, first from the point of view of the hydrodynamic forces acting on it during installation. This leads to a theoretical model for the installation process. Second, we shall consider the package as a subminiature optical fiber cable, and examine its optical performance during manufacture and temperature cycling, which leads to a theoretical model of the temperature performance of the package. Finally, we will describe a trial field installation using this cabling technique.     

Fiber cable design and characterization

Optical-fiber cable design differs from the design of metallic cables principally because of two factors: i) the physical properties of fibers are more limiting than those of metals, and ii) the transmission performance of a fiber can be altered by cabling operations due to a phenomenon called microbending. After reviewing these factors, methods are considered for mitigating their effects by appropriate design procedures. This leads to the consideration of different types of cable structures. In order to evaluate an optical cable design, it is necessary that its important mechanical and optical properties be characterized. The tensile, bending, and impact performance, as well as cabling added loss, temperature dependence of loss, and concatenated fiber bandwidth are then considered. The paper concludes with a discussion of "long-term" stability of optical cables.     

Design and characteristics of multi-hundred-core optical-fiber cable for use in subscriber feeder lines

This paper describes a design method for optical-fiber cable consisting of optical-fiber ribbons encased in loose tubes. The influence of excess fiber length on optical loss in a loose tube is evaluated and the required clearance is obtained. The optimum combination of the clearance and the tube stranding pitch is obtained in order to suppress fiber strain. The tube dimensions are also discussed and are determined to protect fiber ribbons from lateral load. A 600-fiber-structure cable is manufactured according to the obtained design results; the transmission and mechanical performances are confirmed to be excellent.     

超长光电复合海缆光缆单元的研发与制造

本文介绍了超长光电复合海缆光缆单元的研发和制造,该光缆单元是35KV光电复合海底电缆中的通信单元,由于海底电缆接续技术复杂,不允许有接头,要求单盘光缆长度超过36公里,本文论述上述光缆的基本结构、设计思路、工艺控制、试验结果等。     

First sea trial of 1.5-μm submarine optical fiber cable

The first sea trial of submarine optical fiber cable using dispersion-shifted fibers is described. The discussion covers the fiber structural design, cable manufacturing results, fiber splicing, cable laying results, and a high-accuracy measurement technique for optical loss and chromatic dispersion. The results demonstrate the feasibility of long-span, high-capacity 1.5-μm submarine optical fiber cable     

Optical Fiber Cable Installation Techniques

When installing junction optical fiber cable, which essentially must be longer than conventional metallic-conductor cable to effectively reduce splice loss, the applied tensile load must be within tolerable limits to prevent an increase in loss and a decrease in lifetime. It has recently become possible to meet this requirement through the development of a new cable installation system which makes use of a modified cable pulling truck and a new intermediate cable pulling machine. Furthermore, this new installation system, capable of achieving a 1.0-1.5 km installation length for all types of cable accommodations, has already been put into practice. In addition, this paper presents three new cable installation techniques for facilitating subscriber optical fiber cable installations under various environmental conditions: a tension-controlled pulling technique, a cable pulling eye attachment technique, and a cost-effective damage-free cable installation technique in older buildings.     

光缆干线网设计中有关问题的探讨

针对天津市二级光缆干线网工程的设计,就光缆网的可靠性,光纤类型、光缆容量及扩容方式的选择及中继段长度的计算等问题进行了探讨。     

光缆施工中的接续技术探讨

在光缆施工工程中,光纤接续技术和接头损耗的测量是影响工程质量的一个重要因素。文中首先对光纤熔接损耗产生的具体原因进行了分析,然后从光缆的选择、施工的环境、工具的选用等方面提出了有效降低光缆施工中接续损耗的措施,最后针对带状光缆的特点,对如何降低带状光缆的接续损耗和提高损耗测试精确度提出了相关建议。     

Simple-structure optical fiber cables manufactured withoutstranding processes

The design and characteristics of an optical-fiber cable which can be manufactured in one tandem process have been described. The structural design has been made in view of attaining stable transmission characteristics and long-term reliability. The relation between excess fiber length and cable structure was investigated. Optical loss increase due to excess fiber length was clarified. The fabricated cable has the following advantageous characteristics: (1) fiber strain did not occur when the cable was elongated by less than 0.2%; (2) the loss changes were less than 0.1 dB/km due to manufacturing and temperature changes within a range of -20-60°C; and (3) the cable exhibited excellent mechanical characteristics     

光纤复合低压电缆温度分布与光单元传输特性研究

研究线缆发热与光单元传输特性变化之间的关系对光纤复合低压电缆(OPLC)设计及应用十分重要。用COMSOL软件模拟仿真光纤复合低压电缆的稳定运行和短路故障状态,得到其相应的电缆温度分布以及光单元传输损耗特性。选取线缆上不同位置处的特征点进行仿真,结果表明：电缆故障时导体绝缘层内升温较明显,外护套温度变化不明显;光纤温度变化很小,其温度在5 s内只有0.2 ℃的上升。由热膨胀引起的位移很小,使得传输损耗在这2种情况下几乎一样,短路故障对光纤的温度影响不大。设计光单元升温实验得到光缆传输损耗的数据,并与仿真数据进行对比分析。实测温度数据滞后于仿真数据5 s,但与仿真数据变化趋势一致,证明了仿真模型的可靠性和可行性。     

海底光缆系统设计及线路余量的考虑

本文简要介绍了海底光缆系统工程设计的方法和要求以及对海底光缆线路的施工和维护,对于各种余量特别是海底光缆线路维护余量的取定进行了说明,可以作为我国海底光缆系统工程设计中线路维护余量的参考.     

A strain sensor using twisted optical fibers

A sensor using twisted optical fibers to detect the strain distribution along the length of an object is discussed. This sensor is based on the optical loss due to fiber curvature. The distributed strain along the sensor axis is converted into distributed optical loss. The relation between the strain and optical loss is theoretically derived and experimentally confirmed for uniform tensile strain. The dependence of the sensor characteristics on sensor structure and fiber parameter are also shown. Measurement of the strain applied to fibers in an optical cable is also discussed     

市县传输网光线路保护系统的设计和应用

本文首先介绍了某地级市有线市县传输网的拓扑结构和业务类型,然后阐述了光线路保护系统的组成和原理,最后提出了市县传输网光线路保护的设计方案。该方案从光缆长度估算、光功率调整、色散补偿计算等方面入手,详细论述了三个方面的设计方法。     

Subscriber optical fiber cable transfer splicing system usingmechanically transferable connectors

An optical fiber cable transfer splicing system is developed for use in removing or changing optical fiber cables. The system enables rapid transfer from existing optical fiber cables to newly installed ones. The transfer is carried out synchronously using two mechanically transferable connectors which terminate the optical fiber cables at two different points, such as manholes. Before the transfer splicing, the system identifies a fiber ribbon in order to avoid mistransfer. A transfer time of less than 30 ms was achieved. The fiber ribbon was identified with a loss, from an identification light source to an identification point, of 35.5 dB. With this system, cable transfer can be faultlessly carried out with only a slight interruption to working transmission systems and circuit quality degradation is suppressed     

Design and performance of ultra-high-density optical fiber cable with rollable optical fiber ribbons

This paper proposes a novel ultra-high-density optical fiber cable that employs rollable optical fiber ribbons. The cable has great advantages in terms of cable weight and diameter, and fiber splicing workability. Moreover, it will be easy to install in a small space in underground ducts and on residential and business premises. The structural design of the rollable optical fiber ribbon is evaluated theoretically and experimentally, and an optimum adhesion pitch P in the longitudinal direction is obtained. In addition, we examined the performance of ultra-high-density cables with a small diameter that employ rollable optical fiber ribbons and bending-loss insensitive optical fibers. The transmission, mechanical and mid-span access performance of these cables was confirmed to be excellent.     

光电复合海缆温度场建模分析及在在线监测中的应用

为了有效监测光电复合海缆的绝缘状况,基于迭代法改进了IEC60287电缆载流量和温度场计算标准,在有限元数值分析软件包COMSOL中基于热电耦合模块建立了110 kV YJQ41300 mm2海缆温度场模型,与改进IEC60287标准比较验证了建模方法的准确性,在此基础上确定了不同载流量下海缆模型最佳的分析范围。建模研究了海缆正常运行和绝缘性能下降情况下载流量和环境温度对光纤温升的影响;采用介质损耗表征绝缘状况,分析获得了典型介损值下光纤相对温升的变化规律。结果表明:正常情况下光纤温升随载流量的增加近似成平方增大,随环境温度的增加近似线性增大,增速较慢;海缆绝缘性能下降时光纤相对温升随tan的增加成正比增大,相对而言,受环境温度的影响很小。根据上述研究,提出了基于光纤相对温升和海缆载流量的介损计算公式和基于光纤相对温升的海缆绝缘状态监测方法。较之现有基于电气量的绝缘监测方法,该方法不易遭受电磁干扰的影响。在光电复合海缆在线监测方面具有参考应用价值。