共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
5.
马磊 《光纤与电缆及其应用技术》2011,(4):10-12
通过对OTDR脉宽对短距离光纤样品衰减系数测试结果影响的分析和环境试验中短距离光纤样品衰减变化测试结果的分析,认为500m及500m以内光纤或光缆样品不适合采用OTDR测试衰减系数,提供测试的光纤或光缆样品应尽可能长一些,在2km左右较为合适。 相似文献
6.
7.
8.
9.
曹维敏 《光纤与电缆及其应用技术》1983,(3)
本文介绍了一种区分光纤固有衰减和扰动作用的实验方法。此方法有助于在逐段光纤上外推完成衰减测试结果,且对于光纤制造过程中的最佳工艺更为有益。 相似文献
10.
王志和 《光纤与电缆及其应用技术》1986,(4)
一、引言单模光纤的研究和应用,促进了单模光纤测量技术的发展。由于光纤衰减是单模光纤系统最重要的参数之一,因此衰减测量技术首先得到了迅速发展。从根本上看,单模光纤的衰减测量方法与多模光纤的衰减测量方法基本相同,而且其注入条件要比多模光纤测量简单,但是鉴于下述理由,对单模光纤衰减测量的要求却高于多模光纤。 (1)单模光纤的衰减比多模光纤小,1.3μm时的典型衰减为0.4~0.7dB/km,1.55μm时的典型衰减为0.2~0.4dB/km,可见单模光纤的衰减大约为多模光纤衰减的 相似文献
11.
主要针对中国联通济宁分公司采用数字光纤分布系统解决深度覆盖的典型案例进行分析,依据对覆盖、质量等指标的实测数据,通过与分布式基站覆盖方式进行全方位的对比分析,为数字光纤分布的后续应用建设提供参考。 相似文献
12.
13.
针对变体飞行器变形机翼气动外形监测需求,提出一种植入式柔性复合蒙皮形状光纤传感方法。通过将光纤光栅传感器植入硅胶薄层,并与聚氯乙烯薄片组成复合蒙皮。建立柔性蒙皮形状传感系统,采用光纤传感解调系统,实验测得不同翼型下柔性蒙皮中光纤光栅反射谱特征及其变化规律;计算出柔性蒙皮弯曲曲率,并重建出柔性蒙皮变形三维形状;采用数字摄影测量系统完成对比测试。研究结果表明:柔性复合蒙皮变形光纤传感测量与数字摄影测试误差小于4.62%,光纤传感灵敏度达到245.5 pm/m-1。验证了植入式光纤传感方法的有效性,为变体飞行器变形机翼气动外形监测提供了参考。 相似文献
14.
通过对ONU弱光的ODN链路衰耗进行分析,发现ODN链路的下行衰耗严重超标的现象,在用OTDR进行故障定位、并测试光纤在相应波长的宏弯损耗后,得出光纤的宏弯损耗是导致ODN链路下行衰耗超标的原因;进一步对ODN链路的入户段光缆进行衰耗测试,从而验证了宏弯损耗是引起ONU弱光的主要原因。 相似文献
15.
16.
针对动基座光电稳瞄跟踪系统扰动隔离度、跟踪问题进行了工程研究,介绍系统总体构成及采用光纤陀螺应用于系统消除基座扰动、跟踪大动态目标的稳瞄跟踪系统的工程设计原理,研究了基于光纤陀螺速率稳定环的稳定机理、光纤陀螺的工程应用要求、电流环、稳定环路、系统跟踪控制器的设计方法,最后根据设计原理和方法研制出一套装备并给出了试验结果及跟踪效果图. 相似文献
17.
The distributed optical fiber temperature sensor system based on Raman scattering has developed rapidly since it was invented in 1970s. The optical wavelengths used in most of the distributed temperature optical fiber sensor system based on the Raman scattering are around from 840 to 1330 nm, and the system operates with multimode optical fibers. However, this wavelength range is not suitable for long-distance transmission due to the high attenuation and dispersion of the transmission optical fiber. A novel distributed optical fiber Raman temperature sensor system based on standard single-mode optical fiber is proposed. The system employs the wavelength of 1550 nm as the probe light and the standard communication optical fiber as the sensing medium to increase the sensing distance. This system mainly includes three modules: the probe light transmitting module, the light magnifying and transmission module, and the signal acquisition module. 相似文献
18.
基于光纤导光的数字全息微形变测量系统 总被引:1,自引:1,他引:0
建立基于光纤导光的数字全息干涉微形变测量系统,首先,利用1×2单模光纤耦合器将激光源输出光分为照明光和参考光,实现光路结构简单、紧凑和稳定性好;然后,通过短焦距和长焦距准直透镜分别对照明光和参考光进行准直扩束,使得参物光强度接近1∶1,从而获得高信噪比的数字全息图。利用基于数字全息的双曝光方法对钢板的波长量级微形变进行实验测量。通过全息记录、再现及相位解包裹得到高精度的测量结果。实验结果表明,建立的基于光纤导光的数字全息微形变测量系统具有光路简单、稳定性好等特点,而且测量精度高。 相似文献
19.
Fiber amplifiers play an important part in optical transmission systems to overcome the impact of attenuation. Together with the transmitter and receiver the positions of amplifiers on the optical path as well as the design of the amplifiers itself determine the bit error probability of the digital communication link. We present a simple method how to derive the optimum configuration for an optical transmission link with cascaded fiber amplifiers for an attenuation limited system. The bit error probability is calculated in dependence of the positions of the line amplifiers and the lengths of the doped fibers for systems with and without booster and optical preamplifier. In a first step we search the optimum configuration by numerical minimization of the bit error probability for a given transmission length, transmitter power and optical receiver. We have found a very simple rule how to determine the lengths of the transmission fibers and the doped fibers of the amplifiers for the minimum bit error probability when the length of the first transmission fiber is given. Therefore, the search for the optimum configuration reduces to the search of the appropriate length of the first transmission fiber which results in an enormous reduction of computing effort. We have investigated the effect on the bit error probability when one deviates from the optimum configuration. For the case, when the transmission length is reduced me have found that the bit error probability decreases always, when the lengths of the single transmission fibers are cut 相似文献
20.