光时域反射仪(OTDR)的研制

研制出了一台初步达到市场商品化标准的光时域反射仪.阐述了光时域反射仪的工作原理和制作方法,对它的每个组成部分,包括光器件、电子器件以及测量软件都做了说明.通过对光纤样品的测量,分析了这台光时域反射仪的功能与测量效果.     

长距离分布式光纤传感技术的分析

基于布里渊光时域分析,阐述长距离分布式光纤传感技术的特点,相位敏感型光时域反射仪在较长距离的管道的安全测量中的应用。     

基于高速单光子探测的光时域反射测量

针对传统光时域反射仪(OTDR)激光出射功率高、累计时间长、测量分辨率低的问题,提出了将高速InGaAs/InP雪崩光电二极管单光子探测器应用于光时域反射测量的方法.单光子探测器的工作重复频率为1 GHz,可实现"准连续"探测,无需扫频即可快速捕获单光子水平的回返光信号并输出.该方法实现了出射光脉冲宽度为50 ps、峰值功率为10 mW,测量距离为50 km,距离精度小于10 cm,且事件盲区小于1 m的光时域反射测量.     

光时域反射仪在有线广播电视网络中的应用

介绍光时域反射仪的工作原理、测试故障点的分析，重点介绍接头损耗的计算和分析方法，提出在使用光时域反射仪时要注意的几个问题。     

光时域反射仪的原理与使用

伴随着光缆在有线电视系统中的广泛应用 ,光时域反射仪 (ＯＴＤＲ)在网络改造和维护中的作用显得越来越重要。下面就ＯＴＤＲ的工作原理、组成方框图、测试结果分析和实际操作的经验谈谈体会。1　背向散射原理及组成方框图光时域反射仪又叫光纤分析仪 ,它的工作依据是光的背向散射原理。光纤的背向散射是由瑞利散射和菲涅耳反射引起的 ,菲涅耳反射是由折射率变化引起的 ,一般发生在接续点、对接处和光纤的端面。而背向散射是由于介质不均匀而引起的散射光中 ,会有一部分光沿着光路传输的相反方向传回发送端。光时域反射仪就是利用光纤中背向…     

OPGW断股状态的光学监测技术研究

针对OPGW(光纤复合架空地线)易发生断股的现象,提出了采用布里渊光时域反射仪测量其内部光纤应变的断股检测方法。实验中将一段OPGW的两端固定在拉力机上并施加固定的拉力值,逐渐增加OPGW中断开的单丝数,记录布里渊光时域反射仪测量的光纤应变值。实验结果表明,该方法可实现对25%以上的断股区域截面积比的监测,为在线监测OPGW断股状态提供了一种新的思路。     

布里渊散射分布式光纤传感器

介绍了基于布里渊分布式光纤传感器的进展和发展趋势,以及应用后向布里渊散射测量光纤温度／应变的基本原理。介绍了基于光时域反射仪发展起来的BOTDR（布里渊光时域反射）、BOTDA（布里渊光时域分析）及BOFDA（布里渊光频域分析）分布式光纤传感器的原理及各种实施方案,并指出还存在的问题。     

产品推介

DS3620光时域反射分析仪(OTDR)产品概述DS3620光时域反射分析仪(OTDR)是最新推出的高性能微型光时域反射分析仪,能显示光纤及光缆的损耗分布曲线,测量光纤及光缆衰减系数、两点间损耗和接头损耗、反射损耗,测量光纤及光缆长度、两点间距离,     

有线电视系统光纤测量技术

阐述有线电视系统光纤的测试测量中存在的一些问题。并用数学分析方法阐述光时域反射计(OTDR)测量光纤工作原理。     

光时域反射仪在工程测量中的几个问题

在光缆线路的施工维护中,常用光时域反射仪提高测量光缆长度、光接头损耗的精度,采用选定准确的折射率和换算系数,选拔好的动态范围与脉冲宽度,可减小盲区效应,增大光缆长度测量范围。     

OTDR performance enhancement through erbium fibre amplification

By employing erbium fibre amplification of both the outgoing transmitter pulses and the returning backscatter signals of an optical time domain reflectometer (OTDR), a substantial increase is achieved in the one-way dynamic measurement range. First experimental results are presented showing almost 10 dB net improvement in OTDR range, with the potential established for performance increases of up to 20 dB one-way. The prospects are discussed for such performance improvements both in high-resolution OTDR applications and for long-distance fault location.<>     

新型光时域反射计在无源光网络中的应用

提出并实验验证了一种利用自主研制的OTDR来有效定位PON的支路断点或异常损耗事件的方法,讨论了在PON的测量中OTDR面临的新问题和新要求.     

Simulation method of reflectance measurement error using the OTDR

This letter presents an algorithm relating two different optical time-domain reflectometer (OTDR) reflectance measurement methods. From the impulse response of an OTDR, and the attenuation and reflectance values of a reflective event supplied by the OTDR operating according to a first classical implemented method, the algorithm allows the determination of the reflectance that would be measured according to a second more accurate method. Over a 10-dB comparison range the deviations between experimental results and those obtained with the proposed algorithm do not exceed 0.5 dB     

Measurement of Raman scattering in single-mode optical fiber byoptical time-domain reflectometry

The measurement of the Raman scattering in a single-mode optical fiber using optical time-domain reflectometry (OTDR) is reported. The OTDR technique makes it possible to determine the power level of the pump and Stokes components along the fiber without cutting it back, and to estimate Raman scattering parameters in a reliable manner. The measurement method is described and experimental results are discussed. It is concluded that the power conversion process to higher Stokes components has been clearly displayed without cutting back the fiber     

Optical time domain reflectometry using an M-ary FSK probe andcoherent detection

This paper proposes a new approach to enhancing the performance of optical time domain reflectometry (OTDR). This approach launches a probe signal modulated in the M-ary FSK format into a test fiber and detects the backscattering by coherent detection, which offers excellent frequency discrimination, followed by simple signal processing to recover the fiber impulse response. Fault location experiments verify the theoretical prediction of that the proposed approach reduces the measurement time to 1/M without sacrificing measurable dynamic range or spatial resolution. They also show that the approach is effective in reducing fluctuations in the OTDR trace. It is experimentally confirmed that OTDR with the proposed approach is feasible for long haul transmission systems     

Implementation methods of repetitive sampling on an OTDR for alignment of ghost reflection in short-period measurement with a short-length fiber

This paper discusses implementations of a repetitive sampling measurement for OTDR considering ghost effect for short period measurement with a short-length fiber. Repetitive sampling is done to acquire higher equivalent sampling rate with a low sampling clock in the data acquisition. However, the repetitive sampling can cause misalignment of ghost reflection which produces a distortion. This study analyzes the effect of ghost on the repetitive sampling measurement result. The implementations which can be categorized based on the delay object, delaying sequence, and delay looping steps are analyzed for the distortion possibility and proposed to avoid a mis-aligned ghost reflection measurement. The experiment with an OTDR that has an equivalent sampling rate of 10 GHz obtained using a 10 MHz sampling clock and 100 ps delay is shown to validate the method.     

利用OTDR进行精确的测试

从理论上推导了OTDR测试光纤长度、衰减常数、衰减、接头损耗、回波损耗的原理 ,并在此基础上分析了影响OTDR测试精度的因素以及OTDR测量误差的来源 ,最后指出了在利用OTDR进行测量时应注意的地方。     

对OTDR测试光纤链路某些问题的分析

文章从OTDR的测试原理出发,对怎样更精确地测试光纤长度、接头损耗等问题进行了分析,指出要注意OTDR测试光纤链路时与光端机的相互影响.     

Continuous measurement of optical fibre transmission loss characteristics during drawing process

An online measurement method using an optical rotary connector is proposed for continuously monitoring optical fibre loss characteristics during manufacture. This method provides a complete transmission loss spectrum and OTDR measurements of optical fibres during the drawing process. The results coincide with corresponding offline cutback measurements to better than ±0.2 dB/km.     

在最小二乘法模式下幻峰对OTDR测试光纤接头损耗的影响

描述了幻峰及其对OTDR测试光纤线路的影响,重点从理论上分析了OTDR在“最小二乘法”模式下的工 作原理,并对OTDR在“最小二乘法”模式和“两点法”模式下测试光纤接头损耗进行了比较。