光纤光栅和环行器构成的多路光分插复用器

讨论由光纤光栅和光环行器构成的光分插复用器的结构,性能和特点,提出采用一段刻有多个光纤布拉格光栅的光纤,两个光环行器,WDM复用器和解复用器等器件,构造能够对WDM的多个信道实施分插操作的光分插复用器,该光分插复用器的插入损耗要比简单地把多个单路的光分插复用器进行级联时小得多,波分复用全光网络中的光分插复用技术,是实现波分复用网络的关键技术之一。     

基于光纤光栅的温度不敏感光分插复用器研究

报道了一种基于光纤光栅的温度不敏感光分插复用器(OADM),该光分插复用器下载中心波长1 551.72 nm,邻道串扰小于-30 dB.采用两种不同热膨胀系数的材料对光纤光栅进行封装,在环境温度范围为-18℃～50℃时,中心波长变化0.000 4 nm/℃,温度稳定性远高于未补偿光栅指标0.01 nm/℃.     

利用光纤光栅研制分插复用器

在波分复用的光纤通信系统中,分插复用技术需要低损耗、小型化的、稳定的、可靠的器件。使用光纤光栅,可以 制作多种结构的分插复用器,本文对多种基于光纤光栅的分插复用器的结构和原理进行了研究。     

基于马赫-曾德尔干涉仪和光纤光栅的光分插复用器

光分插复用器(OADM)是波分复用(WDM)系统中的关键器件之一。提出了一种结构新颖的基于马赫-曾德尔(M—Z)干涉仪和光纤光栅(FBG)的光分插复用器，它由两个三端口光环形器、一个光纤光栅和一个马赫-曾德尔干涉仪组成，马赫-曾德尔干涉仪起着光开关的作用。对光分插复用器的输出特性进行了实验研究，实验中调节干涉仪的臂长差，可以实现信号的上下载或直通功能，上下载时通道的隔离度大于20dB。这种结构的光分插复用器具有结构简单、体积小、价格低等优点，在波分复用技术中具有实际应用价值。     

一种新型光分插复用器及其应用

提出并分析了一种基于光纤光栅的新型光分插用器（OADM）。与基于光纤光栅的普通型OADM相比，具有更小的同频串扰，下载端口的同频串扰小于－80dB，上载端口的同频串扰小于－50dB；而且可以上下载任意波长信号。     

基于FBG的新型双向传输可调谐光分插复用器

提出了一种基于FBG(光纤布拉格光栅)的新型双向传输可调谐光分插复用器,同时对该结构的复用解复用原理进行了阐述,通过Optisystem软件验证了结构设计和理论分析的可行性。仿真结果表明,下载波长的边模抑制比在20dB左右。这种器件具有灵活度高、器件利用率高等特点,在波分复用系统中两条线路互为冗余,提升了系统的容错性,有望在光网络中得到应用。     

用于光分插复用器的一体化光纤光栅耦合器制备工艺及实验研究

基于熔融拉锥耦合器制作工艺及相位掩模布拉格光纤光栅制作工艺,初步制作了一体化光纤光栅耦合器(FGC),通过对影响初制器件特性的工艺因素进行分析和实验验证,提出了改进的一体化光纤光栅耦合器制备工艺,成功制成了一体化光纤光栅耦合器,进行了器件特性测试实验研究,即光波上行复用(OAM)、光波下行复用(ODM)实验,为一体化光纤光栅耦合器的制备提供了参考。     

基于熔锥式100%耦合器中紫外写入布喇格光栅的光分插复用器

本文报导了第一次实现的基本熔锥式１００％耦合器的耦合式紫外光写入布喇格光栅的一种简单而稳定的光分插式复用器。以低的插入损耗演示了上，下线功能。     

可调谐光分插复用器的一种新结构

此文讲述可调谐光分插复用器的一种新半导体薄膜并以微光学技术生产了样机。可调范围大于８ｎｍ且测出插入口和分出口之间具有５５ｄＢ以上的高隔离度。     

双向波长上下路光分插复用器

通过对科技文献的归纳总结和分析比较,介绍了四种实现双向波长上下路的光分插复用器结构和工作原理,它们是：（1）基于FBG和多口光环形器;（2）基于波导光栅路由器和FBG;（3）基于阵列波导光栅（AWG）;（4）基于解复用器／复用器对和光开关的OADM结构。     

Investigation of superstructured fiber Bragg grating-based OCDMA system

The bit error rate (BER) performance of a superstructured fiber Bragg grating (SSFBG)-based optical code division multiple access (OCDMA) system is investigated with different input pulse widths and grating refractive index modulation amplitudes, and the corresponding crosstalk ratio is considered at different data-rates. Simulation results show that increasing the input pulse width or grating refractive index modulation amplitude will degrade the BER performance apparently. Moreover, with fixed code length and chip-rate detection, a lower data-rate system has better tolerance to an increasing input pulse width, while a higher data-rate system has better tolerance to an increasing grating refractive index modulation amplitude.     

Monitoring respiration and cardiac activity using fiber Bragg grating-based sensor

This paper shows the design of a fiber-based sensor for living activities in human body and the results of a laboratory evaluation carried out on it. The authors have developed a device that allows for monitoring the vibrations of human body evoked by living activities--breathing and cardiac rhythm. The device consists of a Bragg grating inscribed into a single mode optical fiber and operating on a wavelength of around 1550?nm. The fiber Bragg grating (FBG) is mounted inside a pneumatic cushion to be placed between the backrest of the seat and the back of the monitored person. Deformations of the cushion, involving deformations of the FBG, are proportional to the vibrations of the body leaning on the cushion. Laboratory studies have shown that the sensor allows for obtaining dynamic strains on the sensing FBG in the range of 50-124 μ strain caused by breathing and approximately 8.3 μstrain induced by heartbeat, which are fully measurable by today's FBG interrogation systems. The maximum relative measurement error of the presented sensor is 12%. The sensor's simple design enables it to be easily implemented in pilot's and driver's seats for monitoring the physiological condition of pilots and drivers.     

一种新颖的光纤光栅电流传感器

提出并验证了一种光纤光栅电流传感装置,该装置利用洛氏线圈把大电流转换为低电压,借助压电陶瓷的电致伸缩效应把低电压转换为光纤光栅布拉格波长的漂移,最后通过干涉解调技术把波长漂移信号转化为相移信号,由相移值确定待测电流的变化量.实验证明在0～400 A的范围内,电流传感灵敏度为0.0473 rad/A,与理论值0.0589 rad/A基本吻合.     

新型光纤Bragg光栅振动传感系统

分析并实验研究了一种基于机械感生长周期光纤光栅(MLPFG)解调的新型光纤Bragg光栅(FBG)振动传感系统。利用机械线加工技术(MLPT)为制作周期为600μm、长为60mm的不锈钢槽板,采用机械感生法写制了中心波长1539.820nm、谐振线性边带大于6nm的MLPFG作为滤波器。选用中心波长为1542.400nm、3dB带宽为0.3nm的FBG设计振动传感器,通过附加电磁阻尼提高了稳定性,扩大了无失真频率测量范围。实验表明,该振动传感系统具有良好的动态响应特性,响应频谱与激振信号完全吻合,频率测量范围为10～3×103kHz,并具有良好的冲击振动响应。     

光纤布拉格光栅温度不敏感振动传感器

介绍了一种新型的基于光纤布拉格光栅的温度不敏感的振动传感器.将光纤光栅倾抖粘贴在直角三角形悬臂梁的侧面,沿垂直方向的振动将导致悬臂梁沿长度方向的曲率周期性变化.悬肴梁弯曲使光纤布拉格光栅带宽展宽,其反射带宽和反射光强随着自由端挠度的变化而改变.在振动测量过程中,以传统的电阻应变片的测量结果作为此光纤光栅振动传感器的参照对比,两者所测得的振动频率相差小于0.5%.此外,由于光纤布拉格光栅的反射带宽和反射光强不随温度改变,所以此振动传感器具有温度不敏感性.     

一种新颖的高灵敏度光纤光栅压力传感器

提出一种双波纹管结构封装的高灵敏度光纤布拉格光栅(FBG)压力传感器,从理论分析了该器件的传感机理。研究结果表明,该FBG压力传感器可实现0～1.2 KPa压力测量,灵敏度达到688.2 pm/kPa,线性拟合度达到0.9973,适用于液位小范围变化的高精度检测。     

Fiber Bragg grating-based large nonblocking multiwavelengthcross-connects

Multiwavelength cross-connects (WXCs) will play a key role to provide mare reconfiguration flexibility and network survivability in wavelength division multiplexing (WDM) transport networks. In this paper, we utilize three different fiber Bragg grating (FBG)-based P-type, S-type, and N-type building blocks with optical circulators and related control devices for constructing large rearrangeably nonblocking N×N WXCs. The P-type building block is composed of certain “parallel” FBG-element chains plated between the control devices of two large mechanical optical switches (OSWs). The S-type building block consists of a “series” of FBG elements and the control device of 2×2 OSWs. The nonswitched N-type building block includes a “series” of FBG elements with appropriate stepping motor or PZT control devices. All FBG elements, each with central wavelength corresponding to equally or unequally spared WDM channel wavelengths, with high-reflectivity are required. Large N×N WXC structures, with minimum number of required constitutive elements, based on a three-stage Clos network are then constructed. We investigate their relevant characteristics, compare the required constitutive elements, and estimate the dimension limits for these WXC architectures. Other related issues such as capacity expansion, wavelength channel spacing, and multiwavelength amplification are also addressed     

All-optical generation of microwave and Millimeter wave using a two-frequency Bragg grating-based Brillouin fiber laser

A novel all-optical technique for microwave/millimeter-wave generation using two-frequency fiber Bragg grating (FBG)-based Brillouin fiber laser is presented. The mechanism for the microwave and millimeter-wave generation is theoretically analyzed. An approximately 33-GHz millimeter wave can be achieved through mixing the pump wave with the third Stokes' wave. In the experiment, an 11-GHz microwave signal is attained. The microwave frequency can be tuned by varying temperature of the fiber Fabry-Pe/spl acute/rot cavity of the Brillouin fiber laser. A more than 100-MHz tuning range around a frequency of 11 GHz is experimentally achieved.     

啁啾光纤布拉格光栅电流传感器

为了测量通电螺线管中的电流,设计了一种基于 光纤布拉格光栅(FBG)啁啾效应的电流传感器。磁场 中的圆盘形软铁受到通电螺旋管线圈磁场力的作用,引起矩形悬臂梁变形,从而导致粘贴在 悬臂梁侧边的 FBG的反射光谱带宽发生变化,其大小与电流强度成平方关系。利用光谱分析仪(OSA) ,通过检测FBG反射谱带宽的变化量,可以得到被测电流强度的大小。当OSA的分辨率为0.02nm时, 测量范围达到了27.1~1000mA。实验结果表明 ,FBG反射光谱带宽的变化量对温度变化不敏感, 当温度从－15℃变化到45℃时,3dB带宽的 最大变化约为5pm。实验结果和理论分析一致,表明本文该方案切实可行。     

A novel dual-wavelength fiber Bragg grating and its application in fiber ring laser

A novel method for fabricating dual-wavelength fiber Bragg gratings (FBGs) by using one phase mask is developed. The method is based on a double-exposure technique. Our technique lends itself to writing gratings with controllable reflectivity and separation of two Bragg wavelengths. A grating with two equal transmission peaks of 20.25 dB is obtained by this method and the separation of the two Bragg wavelengths is about 0.8 nm. With the grating, we demonstrate a dual-wavelength erbium-doped fiber ring laser whose interval of the two peaks is 0.8 nm. The laser's peak powers can get 3.1 mW above and have a good stability.