Effect of Brillouin scattering on optical fibre communication usingsolitons

The limitation imposed by the Brillouin effect on both bright and dark solitons is examined. Bit rates in excess of 100 Gbit/s are allowed, although WDM or sliding filters must be used with bright solitons     

基于分布反馈激光器布里渊散射的高精度光谱测量

实现了一种基于光纤中受激布里渊散射(SBS)效应 的高分辨率光谱测量技术。使用连续可调谐分布反馈(DFB) 激光器作为泵浦光,与待测信号光在单模光纤(SMF)中发生受激布里渊放大相互作用,由此 实现对待测光的高分 辨率光谱测量与分析。DFB激光器的波长扫描通过高精度温度调谐来实现。与相关报道 中使用的外腔 可调谐激光器对比,DFB激光器具有体积小、成本低的优势。同时在波长扫描过程中,对DFB 激光器的输出光进行自 拍频处理获得其实时扫描速率,以此校正激光器的实时扫描波长,提高测量准确度。实验 初步验证了本文高分辨率光谱测量技术的可行性,并获得了0.24pm 的光谱分辨率。     

Multilayer multimode optical fibre

Multilayer multimode fibres are considered by means of the ray theory, and the optimal distribution of refractive index with respect to pulse broadening is found. It is concluded that even with a low number of layers we can reduce pulse broadening significantly. Low sensitivity to the variations of refractive index distribution is predicted.     

20-km distributed temperature sensor based on spontaneous Brillouin scattering

We report on a novel experimental setup for distributed measurement of temperature, based on spontaneous Brillouin scattering in optical fiber. We have developed a mode-locked Brillouin fiber ring laser in order to generate the dual frequency source required for a heterodyne detection of the backscattered signal. This relatively simple system enables temperature measurements over 20 km with a spatial resolution of 7 m.     

布里渊散射的分布式光纤温度传感器的研究进展

提要：基于布里渊散射的分布式光纤温度传感技术凭借着其独特的优点,在国内外引起了广泛的关注,成为了一大热点研究,本文综述了基于布里渊散射的分布式光纤温度传感技术的研究现状。在简单介绍了布里渊测温原理的基础上,针对目前布里渊散射的光纤温度传感器存在的在测量范围以及空间分辨率上的缺陷、不足,重点介绍了布里渊散射的分布式光纤温...     

Optical heterodyne carried generation using stimulated Brillouin scattering in birefringent optical fibre

An optical technique for producing a heterodyne carrier frequency suitable for electronic signal processing schemes in sensing applications is described. The technique exploits stimulated Brillouin scattering generated in birefringent optical fibre. A single fibre system is reported which produces a 10.6 MHz output carrier signal, modulated by optical chaos induced instabilities. The implications of the results for future signal processing and sensing schemes based on stimulated Brillouin scattering are then discussed.<>     

基于光纤SBS效应的光存储

光信息存储作为全光交换和路由的关键技术,在未来的全光网络中有着重要意义.介绍了一些最新的利用光纤中的受激布里渊散射(SBS)效应实现光存储的实验方法和研究成果,综述了国内外在利用SBS产生可调控光纤慢光方面的研究进展.     

多模光纤布里渊散射角及频移的分析与计算

为了确定多模光纤布里渊频移的取值范围,进而评价多模光纤布里渊分布式传感系统的性能,从多模光纤的结构出发,根据射线光学理论分析了多模光纤中的布里渊散射过程,提出了确定布里渊散射角取值范围的方法,得到了阶跃型和渐变型多模光纤布里渊散射角的取值范围为两倍的全反射临界角到π,进而得到布里渊频移的变化范围为10.978~11.083 GHz,该结论为多模光纤布里渊分布式传感系统的设计和优化提供了理论依据。     

基于瑞利散射和布里渊散射的自调Q双包层掺镱光纤激光器研究

结合光纤干涉环原理和受激布里渊散射效应数值求解描述双包层掺镱光纤激光器的速率方程,得到构建光纤干涉环的耦合器耦合率及泵浦功率与输出脉冲重频的关系;进一步采用掺镱双包层光纤激光器中光子数守恒的半数值模型得到耦合器耦合率、泵浦功率与输出平均功率、脉冲能量的关系。实验测试了不同泵浦功率对输出平均功率和脉冲能量的影响,实验结果与仿真结果吻合。研究表明:提高泵浦功率只能提高脉冲重复频率和平均功率,并不能提高脉冲能量;选择合适耦合率的耦合器构建光纤干涉环才能获得较高脉冲能量;泵浦功率较高时会激发二阶斯托克斯光脉冲。     

多模光纤布里渊散射效应研究进展

面对人们日益增长的光纤传感需求,多模光纤的容量优势为解决单模光纤的容量壁垒、实现高精度的多参量光纤传感测量提供了新思路。理论分析了多模光纤的模式特性,综述了多模光纤模式耦合及偏振的研究进展,重点介绍了多模光纤中布里渊散射的阈值、增益谱和布里渊频移的国内外发展动态,分析了未来光纤传感的发展方向。     

Effects of stimulated Raman amplification in optical fibre onstimulated Brillouin scattering threshold power

The effects of stimulated Raman amplification in an optical fibre on stimulated Brillouin scattering (SBS) are investigated. There is a surprisingly simple and general relationship between the Raman net gain and the change in the SBS threshold power, with almost no dependence on fibre parameters     

基于受激布里渊散射的微波光载波信号光谱检测

提出一种基于受激布里渊散射检测微波光载波信号光谱的方法。利用受激布里渊散射窄线宽的特性,解决了调制的微波信号频率低于常用的光谱分析仪分辨率时无法检测微波光载波信号光谱的问题,获得了较高的光谱检测分辨率。     

基于布里渊散射的分布式光纤技术的研究

介绍了基于布里渊散射的分布式光纤技术的工作原理和研究进展.从改变光纤特性、联合喇曼散射和布里渊散射、检测方法技术以及编码技术等方面简述了基于布里渊散射的分布式光纤技术在提高温度分辨率、空间分辨率和测温精度等方面的改进方法,并探讨了现有技术的局限性,提出发展趋势设想.     

Wavelength-switching fibre laser based on multimode fibre Bragg gratings

A multimode fibre Bragg grating (MMFBG) based wavelength-switching erbium-doped fibre laser is reported. With a simple singlemode fibre to MMFBG structure, a novel wavelength-selection technique is developed to achieve the wavelength-switching by changing the mode coupling condition in the multimode fibre. 31 discrete lasing wavelengths are obtained over a wide wavelength range.     

基于布里渊光时域分析分布式光纤漏油传感器

研究了一种新型基于布里渊光时域分析(BOTDA )的光纤漏油传感器,可在min量级发现小规模 漏油事件,主要用于长距离输油管线、油库等场所的实时漏油监测。通过模拟监测输油管道 输运状态,将 光纤埋敷于特种油敏材料中沿输油管线铺设,用BOTDA仪实时监测光纤布 里渊频移,可快速发 现并定位漏油事件。实验证明了本文技术的可行性,能够在10min内 准确定位小规 模漏油事 件,采用DiTeStSTA-R系列BOTDA仪,在1.7km的传感光纤上实现了 0.1 m的定位 精度。     

光纤布里渊与布喇格光栅共线技术的温度互补偿

为了解决实际工程应用中光纤光栅和分布式布里渊共线技术测试应变的绝对温度补偿方法成本较高、不易布设等问题,采用光纤布里渊和布喇格光栅共线技术应变感知的温度互补偿方法,通过感知探头——双光纤光栅-纤维增强复合智能筋的室内和户外温度补偿试验探讨了该方法的有效性和适用性。结果表明,该方法可以实现光纤布里渊和光纤光栅的准分布式温度互补偿,误差低于8%,在工程接受范围内。此外,该技术还能同时给出应变和温度双参量测试结果,简化了传感系统,降低了布设成本,适合实际工程应用。     

基于高非线性光纤中SBS效应的慢光系统

实验研究了高非线性光纤(HNLF)中受激布里渊散射(SBS)的阈值、增益谱、放大特性及其慢光特性,并与普通单模光纤(SMF)进行了对比分析。测量实验表明,HNLF在线宽100MHz的泵浦激光作用下,SBS的阈值为60mW,增益带宽为150MHz,获得的最大慢光延迟量将近15ns,延迟谱与增益谱较好对应。对基于SBS的未来全光通信系统中的高性能光延迟线或全光缓存器具有重要的参考价值。     

Maximum single frequency input power in a long optical fibre determined by stimulated Brillouin scattering

The experimental results of stimulated Brilloum scattering in about a 4 km fibre are reported. The pumping wavelength is 0.71 ?m. The Brilloum shift frequency was measured to be about 25 GHz. The transmitted power was found to be constant, when the input power exceeds about 14.8 dBm. The saturated transmitted power was 0.5 dBm, which corresponded with the output when 14.8 dBm input power was coupled and only linear fibre loss (about 4.0 dB/km) was assumed.     

Demodulation scheme fibre interferometric sensors employing laser frequency switching

A demodulation technique suitable for use with fibre interferometric sensors is described. The scheme employs a frequency switched diode laser and an unbalanced Mach-Zehnder interferometer. Minimum phase sensitivity ? 2× 10-5 rad is obtainable, and can be shown to be limited by the laser phase noise.     

光纤传感系统评述

光纤传感器对于传感各种物理量有着很大的潜力，其中包括声音、磁场、电流、温度、荧光、加速度、速度和旋转率等等。国外已形成一个新的有前途和研究领域，估计到八十年代后期将会进入实用阶段。本文主要介绍光纤传感器的优点和基本原理。