谐振式光纤陀螺多激光器系统相对频率噪声抑制

设计了用于谐振式光纤陀螺系统中两个半导体激光器相对频率噪声抑制的全光纤光路外差式光学锁相环,建立并分析了陀螺精度需求和外差式光学锁相环关键参数的关系,同时对外差式光学锁相环全数字反馈控制环路进行了设计和仿真.通过实验对设计的系统进行性能验证.结果表明两个主从激光器的中心频率实现了参考频率源频率的锁定,且拍频激光中心频率相对于光纤环形谐振腔谐振频率偏离幅值减小了15dB.     

光纤制导技术及其应用

介绍了光纤制导系统的组成；分析了导弹与控制站之间数据传输、转换、处理和制导原理；采用单模双通道波分复用技术和时分复用技术，通过对两种不同波长光的耦合、分离，实现了单根光纤双向传输，给出了光纤制导导弹中的技术关键和要求，包括制导光纤、图像传感器、双向通信传输技术、光源器件和光检测器件等．     

基于双折射效应的普通单模光纤频率偏移器和偏振控制器

本文介绍了利用普通单模光导纤维弯曲产生的双折射效应而研制成的频率偏移装置和偏振控制装置.频率偏移装置的单边带抑制达30dB以上,它与光纤偏振控制装置一起是构成全光纤功能型传感器比较理想的光纤元件.     

皮秒光脉冲在光纤中的传播特性测量

文章讨论了皮秒激光脉冲在单模光纤传输中光纤介质的色散及非线性折射率等效应对皮秒光信号的影响，利用时间相关单光子计数系统，观测了皮秒激光脉冲在单模光纤中的展宽及皮秒自聚焦现象，并对光纤中皮秒光脉冲的畸变进行了检测与研究。     

基于空气孔填充的光子晶体光纤与普通单模光纤低损耗耦合研究

提出一种基于空气孔填充的光子晶体光纤与普通单模光纤低损耗耦合方法,并通过光束传播法数值仿真的方式研究了填充物折射率以及填充长度等参数对耦合损耗的影响。结果表明,选择合适的填充参数可以大幅度降低光子晶体光纤与普通单模光纤间的耦合损耗,从而实现光子晶体光纤与普通单模光纤间的低损耗耦合。该方法可适用于多种光子晶体光纤与普通单模光纤之间的低损耗耦合,在光子晶体光纤与普通单模光纤的模场严重失配的情况下,该方法的优势更为明显。     

基于空气孔填充的光子晶体光纤与普通单模光纤低损耗耦合研究EI北大核心CSCD

提出一种基于空气孔填充的光子晶体光纤与普通单模光纤低损耗耦合方法,并通过光束传播法数值仿真的方式研究了填充物折射率以及填充长度等参数对耦合损耗的影响。结果表明,选择合适的填充参数可以大幅度降低光子晶体光纤与普通单模光纤间的耦合损耗,从而实现光子晶体光纤与普通单模光纤间的低损耗耦合。该方法可适用于多种光子晶体光纤与普通单模光纤之间的低损耗耦合,在光子晶体光纤与普通单模光纤的模场严重失配的情况下,该方法的优势更为明显。     

高性能三端口全光纤开关

提出采用２×２和３×３单模光纤耦合器组合成的马赫－陈德尔干涉仪来制作全光纤开关。解决了在连续熔融拉伸两个耦合器组成马赫－陈德尔干涉仪的过程中，由于干涉的作用而无法监视光功率来控制第二个耦合器的分束比的问题。并且由于是连续熔融拉伸，保证了两条单模光纤干涉臂长度的一致，从而提高了单模光纤马赫－陈德尔干涉仪的性能，使得用其做成的三端口压电陶瓷电控全光纤开关具有宽频带的特性，其最小交调达到３０ｄＢ，附加损耗为０．２３ｄＢ。     

扩芯光纤原理及其在光器件耦合中的应用

介绍了两种可以增大单模光纤模场直径并出射准直平行光束的扩芯光纤(ECF)的原理和制作方法。分析了单模光纤熔接渐变折射率多模光纤法通过改变渐变折射率多模光纤的长度和自聚焦参量实现模场扩大缩小的原理,制作的扩芯光纤模场直径扩大到16．6μm,出射光束平行效果较好,轴向耦合容限比单模光纤扩大了近6倍。加热扩芯光纤则是通过控制加热温度和加热时间直接使单模光纤掺杂物质发生扩散,从而实现扩束和光束准直,模场直径达到15．4μm,横向、轴向耦合容限都比单模光纤有很大提高。因此扩芯光纤可以简化单模光纤的耦合对准过程,用来制作新型的单模光纤或掺铒光纤连接器,也可以用于其它光器件中与单模光纤的准直。     

基于半导体光放大器的光脉冲压缩方案的研究

对一种基于半导体光放大器(SOA)和普通单模光纤的光脉冲压缩方案进行了理论分析和实验验证.建立了该方案的理论分析模型,并在此基础上数值模拟了光脉冲的传播过程.计算结果表明,通过合理选取单模光纤的长度,可使50 ps光脉冲压缩到5 ps.实验表明利用普通单模光纤群速度色散导致的脉冲啁啾抵消SOA自相位调制引起的脉冲啁啾,实现了色散补偿及脉冲压缩.     

基于时分复用的多点式环形腔光纤电流传感器

为实现输电线路上的多点电流监测,利用通信用普通单模光纤,设计基于时分复用的多点式光纤环形腔结构电流传感器.多路传感系统共用一套光源、检测设备和数字信号处理系统,在节约成本的同时,提高了利用率.实验中选用双路全光纤电流传感器结构,在两个不同的点同时测量电流,其中一测量点对0~600A范围内的电流进行测量,另一测量点对0~1 500A范围内的电流进行测量.对实验数据进行线性拟合,结果表明:循环次数取8比较合适,此时系统具有比取2时高约3~4倍的灵敏度;两个测量点光信号的偏振态与电流之间有良好的线性关系,两个传感单元的灵敏度不同,而且相互之间没有串扰是各自独立的传感系统.     

Extrinsic fibre-optic sensors for remote measurement: Part two

The impact of incorporating fibre optic components into well established optical techniques such as laser Doppler velocimetry, non-contact vibration measurement, holography and light scattering, is discussed in the two sections of this paper. The possibilities range from simply including a fibre ‘optic link’ in a conventional system to facilitate measurements in difficult or remote areas, to the realization of entirely new optical configurations in which virtually all of the conventional optical components have been replaced by their fibre-optic equivalents. In part two laser velocimetry, vibration measurement, holography and scattering are discussed.     

Development of fibre optic sensing systems—A review

A novel type of sensing system, in which we utilise optical fibres as sensing elements or transmission lines, is currently being developed. Some fibre optic sensing systems have already been put to practical use. Their advantages are outlined, and the principles, performance, and problems of some typical fibre optic sensing systems are described in detail.     

掺铒光纤放大器及其在光纤孤子通信系统中的应用

讨论掺铒光纤的制造技术和掺铒光纤放大器的放大原理。结果表明,掺铒光纤放大器非常适用亍光纤孤子通信系统对光孤子进行放大。     

Hand-held laser welding of metals using fibre optics

A fibre optic delivery system has for the first time been used in laser welding of metals. The optical fibre is flexible and has a length of 140 cm. It can transmit pulsed energies from a Nd-YAG laser in excess of 25 J with an efficiency of 85%. Potential applications in industry and in dentistry are discussed.     

Fibre optic target reflectivity sensor

This paper reports the principle of operation, the design aspects, experimentation and performance of a fibre optic target reflectivity sensor to examine the correlation between the detector output, variation in material type and the reflectivity properties of the materials tested. The device consists of a fibre optic transmitter, a fibre optic probe, target and a photodiode detector. The fibre optic probe consists of two well-polished PMMA (polymethyl methacrylate) fibres cemented together along some distance over the length. The principle of fibre optic lever displacement sensors is applied. Material effects are examined by preparing a variety of samples namely gold coated mirror, copper, brass, aluminium, steel and galvanized iron using the same polishing techniques. It is found that the response of the sensor changes with change of target surface. The results show that the fibre optic probe is capable of discriminating between materials. With the use of commercially available fibre, source and detector, the set-up proves to be simple, highly sensitive, low cost and versatile one, which can be adopted for on-line measurement or inspection of test components.     

光纤Mach-Zehnder干涉仪系统

介绍了光纤Mach-Zehnder(MZ)干涉仪系统的结构.给出了光纤Mach-Zehnder干涉仪系统中信号光与参考光的干涉原理以及影响干涉光强的因素.同时也分析了光纤耦合器的交叉耦合,另外也给出了PZT的作用.阐述了光纤偏振控制器的结构、工作原理及其对光纤Mach-Zehnder干涉仪系统传感臂偏振态的控制,最后给出了光纤Mach-Zehnder干涉仪系统的应用.     

Port wine spectronephelometry

The main purpose of this research was to create a portable equipment capable of measuring colour and turbidity during production of port wine. Actually, human, chemical and colour analysis are performed in key production stages for quality control. Several wine transformation processes are done without any kind of control. By using a fibre optic illuminator with a tungsten/halogen light source and a small spectrometer with fibre optic input, it was possible to perform angular measurements in wine samples. We have adapted these optical devices with a specially designed mechanical equipment which allows the passage of the wine during production. The spectral measurements were acquired in four different angular positions in a bypass of the mechanical support. This way we could determine colour coordinates and spectral transmittance and turbidity for three stages of a Ruby production. The entire equipment assembly had been previously calibrated in terms of colour and turbidity determination. The obtained results are in agreement with wine transformations between measurements, showing a small variation in colour and a high diminishing in spectral turbidity when filtration was performed. Transmittance has also increased after filtration turning the wine more limpid as it should be for human appreciation.     

The rotation of the polarization in low birefringence monomode optical fibres due to geometric effects

Monomode optical fibres of very low intrinsic linear and circular birefringence have been developed for use in polarimetric optical fibre sensors, most notably the fibre optic current sensor. The polarization of light travelling along such fibres is known to be modified by external stress applied to the fibre. In this paper it is shown that the polarization state may also be rotated if the path of the fibre is bent in a nonplanar curve. A theory is developed which enables the effect to be quantified and the results are shown to agree with some measurements on a fibre bent into a helix.     

High-speed bridges for fiber optic local area networks

Progress in optical fiber communications allows ever-increasing channel capacity for local area networks (LANs). However, there are still many problems to solve with respect to bridges interconnecting these LANs, which constitute a system bottleneck. To eliminate the bridge bottleneck in the interconnection of fiber optic LANs, a high-speed bridge using optical technology is proposed. The proposed optical bridge uses bistable optical devices, such as interference filters, as essential components of its design. As these devices can be easily fabricated, the implementation of this optical bridge is feasible.