光纤布拉格光栅振动传感器的研究进展

随着光纤传感技术的不断发展,光纤布拉格光栅(Fiber Bragg Grating, FBG)振动传感器在实际应用中的复杂振动测量性能愈发优良可靠。基于FBG振动传感器的优势,简略地阐述了FBG振动传感器的工作原理,并介绍了近5年国内研发的部分悬臂梁型、膜片型、铰链型三种结构的优缺点。最后针对FBG振动传感器提出了4个方面的建议,并展望了FBG振动传感器的发展方向。     

基于光纤光栅的温度不敏感的倾斜传感器

提出了一种新型光纤Bragg光栅(FBG)的倾斜传感器,其结构由通过4根等长的刻有光栅的光纤悬挂在圆盘上的重物组成,4根光纤与圆盘的粘接点均匀分布在圆盘边缘,每根光纤的另一端共同下拉一重物,使每根FBG的受力均匀.当整个平台倾斜时,每根FBG的受力发生变化,从而导致每根FBG的反射(透射)中心波长发生变化,并通过光谱仪...     

基于倾斜光纤光栅的温度不敏感振动传感器

提出了一种基于倾斜光纤光栅与多模光纤相结合的温度不敏感振动传感器,其振动传感头是在倾斜光纤光栅与单模光纤之间加入一小段多模光纤所组成。倾斜光纤光栅的反射光谱有布拉格模和包层模两部分组成,其中多模光纤的作用是将倾斜光纤光栅反射包层模耦合到单模光纤的基模。倾斜光纤光栅包层模对外界振动很敏感,通过传感器的包层模平均输出功率完成对外界振动物理量测量。由于采用强度解调的方式,可以大大降低传感器装置的复杂性。实验表明：当传感器温度从20 ℃上升到70 ℃时,传感器的输出平均光功率均方根误差为0.01 μW,其反射光谱平均输出功率影响很小,故可以避免外界温度对测量结果的影响。     

双光纤光栅实现温度不敏感的二维倾斜角传感器

提出并研究了一种新颖的钟摆式光纤光栅(FBG)二维倾斜角传感器,其摆杆顶端采用圆锥结构,两个FBG沿着母线方向并间隔四分之一圆周粘贴在圆锥表面,摆杆下端固定一定质量的重物.在倾斜角发生变化时,圆锥表面产生的沿着母线方向梯度分布的应变场使FBG产生啁啾效应.利用功率谱平坦的宽带光源,通过监测两个FBG的反射光强变化,可实...     

光纤布拉格光栅振动传感器研究

随着光纤光栅传感技术研究的不断深入和振动测试技术发展需求的不断增大,关于光纤光栅振动传感器的研究工作迅速展开。介绍了基于光纤布拉格光栅(Fiber Bragg Grating, FBG)的振动传感器的原理,然后就不同的结构类型对近几年的FBG振动传感器研究进行了归纳,并着重对悬臂梁式和膜片式结构进行了总结。阐述了同种结构类型的不同光纤光栅封装方式的优缺点,分析了现阶段所使用的FBG振动传感器,并提出了影响其性能优化的四点因素。最后对FBG振动传感器的发展作了进一步展望。     

光纤布拉格光栅传感器的温度补偿研究

应力和温度变化引起光纤布拉格光栅(FBG)传感器中心波长漂移的交叉敏感效应制约了光纤布拉格光栅传感器的实用化。在简介光纤布拉格光栅传感器工作原理的基础上,综述了近年来国内外在该领域实现温度补偿的相关技术和消除或减弱传感器温度敏感的方法,阐述了光纤布拉格光栅传感器温度补偿的原理,并分析了每种方法的特点,探讨了光纤布拉格光栅传感器应用中存在的问题。     

一种布拉格光纤光栅加速度传感器

本文介绍了一种基于布拉格光纤光栅 (FBG)的加速度传感器设计。为了克服等截面悬臂梁的局限性 ,该设计采用等强度悬臂梁的形式。结果表明 :该种光纤加速度传感器具有良好的稳定性和较高的分辨率 (0 .0 0 5g) ,适合海洋平台等大型工程结构的加速度测量。     

光纤布拉格光栅加速度传感器研究进展

基于光纤光栅原理的加速度传感器是近年来土木、机电和航空航天等领域研究的热点。简要介绍了基于光纤布拉格光栅(FBG)的加速度传感器的基本工作原理及力学模型,重点阐述了国内外基于光纤光栅的不同结构原理的加速度传感器最新研究进展。按工作频率范围的高低,先后介绍了用于低频和高频测量的加速度传感器的开发研究现状,并介绍了用于多维加速度方向测量的光纤光栅传感器的发展现状,最后对光纤光栅加速度传感器的发展作进一步展望。     

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/℃.     

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     

A temperature-insensitive strain sensor using a fiber Bragg grating

A novel temperature-insensitive strain sensor based on a fiber Bragg grating is demonstrated. The front section of the fiber Bragg grating is fixed to a crystal plate, and the other section is linearly etched by HF acid. The reflected power and bandwidth of the grating vary linearly with strain and is insensitive to temperature variation.     

Light intensity-referred and temperature-insensitive fiber Bragg grating dynamic pressure sensor

Temperature-insensitive fiber Bragg grating (FBG) dynamic pressure sensing based on reflection spectrum bandwidth modulation and differential optical power detection is proposed and experimentally demonstrated. A special double-hole cantilever beam is designed to induce linear strain-gradient distribution along the sensing FBG, resulting in FBG reflection spectrum symmetrical broadening and optical power increase.Based on the theory of optical waveguide and material mechanics, the causation of FBG spectrum broadening under the linear strain-gradient is analyzed, and the corresponding force-to-bandwidth broadening relation and force-to-optical power relation are formulized. FBG spectrum bandwidth and reflection optical power linearly change with applied pressure and both of them are insensitive to spatially uniform temperature variations.For a temperature range from -10℃ to 80℃, the measured pressure fluctuates less than 1.8% F.S.(120 kPa) without any temperature compensation. The system acquisition time is up to about 80 Hz for dynamic pressure measurement.     

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.     

简支梁结构的光纤光栅振动传感器

提出了一种新型的基于简支梁结构的光纤布拉格光栅(FBG)振动传感器,将FBG斜向粘贴在矩形简支梁侧面上,在梁中间设置重物来传感竖直方向的振动信号.实验中使用偏心轮作为振动源,并在梁上粘贴电阻应变片进行对比实验.使用光电探测器(PD)和示波器同时检测传感器受竖直方向振动信号作用时FBG的反射光功率与电阻应变片的响应信号....     

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。     

基于光纤光栅的新型光分插复用器

文章提出了一种基于光纤光栅的新型光分插复用器(OADM),并阐述了此新型OADM结构的复用和解复用原理,它具有插入损耗低、灵活性强和串扰低等优点.为验证结构设计和理论分析的正确性,用OptiSystem软件对所设计的OADM结构进行了仿真实验.仿真结果表明,下载波长的边模抑制比高达20 dB,此新型结构具有良好的性能和...     

数字网络型光纤振动传感系统

设计了一种新型光纤振动传感系统,该系统借鉴光通信中的无源光网络(PON)技术、光纤时分和波分混合复用传感侦测技术组建了数字网络型无源传感网络,系统传感单元的最大容量为32×8,有效地扩大了传感范围,实现了多传感单元系统化的集中管理,在处理算法中采用动态阈值自适应管理,可以根据环境变化实时改变阈值.在报警处理中,采用声、...     

具有自标定功能的光纤光栅位移传感器

为了解决光纤光栅(Fiber Bragg Grating, FBG)位移传感器易受温度、振动等外界因素影响而导致测量重复性差的问题,本文利用磁铁非接触的力传递特性,以光纤光栅为核心元件,工字型梁、永磁体等为辅助元件研究了一种无接触的FBG位移自校准装置。利用移动端磁铁与位置标定端磁铁位置重合时,工字型梁所受磁力最大,进行位置信息的自校准,进而提高FBG位移传感器的测量重复性和测量精度。通过将自校准装置安装在卷尺结构的位移传感器上,对其传感特性展开实验研究,结果表明：在0～360 mm的测量范围内,校准前平均均方根误差为5.838 mm,校准后平均均方根误差为0.953 mm。本文采用自校准装置在很大程度上提高了FBG位移传感器的测量重复性,为位移传感器的环境适应性优化提供了一种新方法。