基于直角棱镜的光纤光度传感器

介绍了一种由两个相同直角棱镜构成的气室。利用其对光束摆动的不敏感性及对光束的反射特性，来提高气室工作的稳定性和检测灵敏度；分析了传感器中光束的传输特性，给出了光束的传输方程、单波长和双波长情况下光度传感器的测量方程；光束在气室内往返的次数N与过两个直角棱镜各自直角棱的对称面的间距d有关，通过调节间距d可选择所需测量灵敏度。测试结果表明，在低浓度测量时，这种光度传感器的灵敏度为普通单程吸收池灵敏度的N倍；在较高浓度时，仅在N为较小的几个值时，传感器的灵敏度与光束在气室内往返的次数N成正比，N较大时，光束在气室内往返的次数对传感器灵敏度的倍增作用减弱。基于直角棱镜的光纤光度传感器特别适合痕量物质的光度测量。     

ZnO镀膜光纤传感器功率耦合效率参数优化

基于ZnO镀膜光纤传感器的几何结构和等效网络模型,建立了目标函数功率耦合效率的数学模型。采用了一种混合粒子群算法对功率耦合效率参数进行了优化,仿真结果表明该算法对于复杂约束下的功率耦合效率模型更有效。通过仿真得到了一系列器件参数数据,对优化后的数据进行了分析,为ZnO镀膜光纤传感器的制作提供了理论参考。     

C型弹簧管光纤压力传感器

本文介绍了一种用Ｃ型弹簧管作为压力敏感元件，采用双面反射进行强度调制的光纤传感原理，实现压力检测。这种传感器可以充分利用光纤的接收特性，有效地解决动态范围与灵敏度成反比的矛盾，并能够消除光源强度变化以及其它因素对测量带来的影响。     

双通道抛物线型多模光纤位移传感器输出特性

本文根据稳态输入条件下光纤输出光强的远场分布导出了发射光纤折射率为抛物线型分布时,双通道非对称光强反射式位移传感器的输出特性参量ф与移位d的关系,理论计算和实际测量的表明,输出特性曲线不存在所谓的光峰结构,输出特性参量φ与位移d是一一对应的单值关系。这种光纤位移传感器的灵敏度仅决定于传感器的结构参数,与不纤中传输的光强无关。改变传感器的结构参数即可改变传感器的测量范围和灵敏度。     

补偿型强度调制光纤传感器测量处理的新方法

对补偿型强度财制光纤感器信号处理的共性的研究提出一种基于自扫描二极管阵列器件作为探测器的信号探测及处理新方法,较好地解决由于信号识别处理对传感性能的影响,尤其适合于多路探测传感器。     

基于ICPSO-BP神经网络的光纤SPR传感器开环系统优化研究北大核心CSCD

表面等离子共振(SPR)传感器开环系统的弊端,对全局搜索粒子群算法(PSO)的早熟收敛问题进行改进,提出了一种动态信息调整且速度可控的改进型合作粒子群算法(ICPSO)。该方法通过在粒子飞行状态控制的迭代方程中引入子群最优信息,较好地保持了粒子多样性,有效地避免寻优飞行中粒子的早熟收敛。进一步将该算法作为BP神经网络的训练算法,建立了更为优化的ICPSO-BP神经网络。最后,利用ICPSO-BP神经网络对光纤SPR开环系统的内部非线性模型进行辨识补偿,分别建立单输入、双输入、三输入的ICPSO-BP神经网络补偿模型,实验及仿真结果表明新算法在测试线性精度和速度上均具有较好的表现,从而保证了光纤SPR良好的线性测试效果,为光纤SPR传感器进一步应用打下一定基础。     

微光纤干涉型生物传感器

光纤生物传感器利用倏逝场效应与待测物质发生相互作用,通过检测生物识别分子与目标分子特异性结合反应引起的光信号变化实现对待测物的检测.光纤传感器由于具有尺寸小巧、可柔性弯曲等优点,从而有望为现代医学提供一种在体原位检测的新手段.微光纤干涉型生物传感器以微光纤模式干涉仪作为换能器,通过光学波导增敏和界面增敏,可实现超高灵敏...     

基于长周期光纤光栅的光纤液位传感器

为了测量液位在警戒值附近变化的情况, 采用新款光纤熔接机制作了一种基于锥形结构的长周期光纤光栅测量液位的光纤传感器, 对传感器进行了理论分析, 搭建了液位传感实验系统, 根据传感器对外界环境的折射率灵敏度, 测量浸没在液体中的光纤长度。结果表明, 在0 mm~12 mm的液位测量范围内, 光纤液位传感器的峰值波长灵敏度和透射功率灵敏度分别是0.700 nm/mm和1.377 dB/nm。该传感器对液位变化测量较为准确, 且采用刻栅方式可有效解决传统长周期光纤光栅中存在的非对称模耦合和偏振依赖性高等问题, 同时具有制作简单、成本低和应用前景广泛等优点。     

光纤Michelson干涉仪型折射率和温度同时测量传感器

基于Michelson干涉仪原理,制作了一种可同时测量折射率和温度的全光纤传感器。传感器由单模光纤和一段长度为5mm的细芯光纤错位熔接而成。对该传感器的折射率和温度响应特性进行理论分析,并在折射率和温度的变化范围分别为1.333 3~1.404 9和20~90℃的环境中对传感器的响应特性进行实验研究,结果表明,随着环境折射率的变化,该传感器输出光谱峰值功率的响应灵敏度为-41.10dB/RIU,而光谱峰值波长对折射率变化不敏感;随着环境温度的变化,该传感器输出光谱峰值波长的响应灵敏度为23.15pm/℃,而光谱峰值功率对温度变化不敏感。因此,通过同时监测传感器输出光谱的功率变化和波长漂移量,可实现折射率和温度的同时测量。该传感器制作简单,测量精度高,在生物医学领域有较好的应用前景。     

光纤电流传感器传感头的结构与理论

光纤电流传感器的传感头是实现电流传感的主要元件.本文推导了传感头的光学传输矩阵,解释了实验中观察到的等效Verdet常数下降和非线性现象.     

光纤传感器

本文介绍了光纤技术的一个新的应用领域——光纤传感器的研究现状。分别介绍了各种传感型及传光型光纤传感器的基本原理、目前取得的结果、尚存在的问题以及可能的应用前景。     

Transmission characteristics of a coaxial optical fiber line

A coaxial optical fiber line is proposed and studied as a long-distance transmission medium. The radial structure consists of a core surrounded by two clads. The inner clad has higher refractive index than the core and the outer clad. Guided modes are thus characterized by a concentrated field in the inner clad and evanescent fields in both the core and the outer clad. Using a rigorous modal analysis, characteristic curves for a monomode coaxial fiber line are presented. It is shown that the zero-dispersion wavelength can be placed at any desired value by proper choice of the refractive index contrast and the fiber dimensions. The proposed coaxial line compares well with the known W-profiled line with respect to ease of manufacture and dispersion characteristics     

Common path heterodyne optical fiber sensors

The common path type of differential heterodyne fiber-optic sensing scheme has been developed. It uses a polarization maintaining fiber as either a sensor or an optical lead and a dual-frequency dual-polarization laser beam. The sensing schemes are applied to the measurements of temperature, strain, force, pressure, rotation rate (gyro), magnetic and electric fields, and thin film thickness. The sensing scheme and main performances for each measurand are described. High precision and high stability as well as good linearity for each measurand are demonstrated     

光纤传感器中微弱光信号检测

对微弱重复信号的检测采用数字累积平均法是一种极有效的技术。实验采用Apple-Ⅱe型机实现了对光纤瓦斯传感系统中4组微弱光信号检测,明显改善了检测系统的功能。本文介绍了系统硬件、软件设计以及有关问题。     

光纤传感器的复用与数据融合

由于光纤传感器中存在交叉灵敏度,阐释传感器的测量及其相互关系是一个重要的课题。采用数据融合技术,对来自不同光纤传感器的信号进行综合处理,建立了分离光纤传感器中的时变耦合信号模型,即多光纤传感器的复用和数据融合的模型。在强度调制、时分调制、光栅调制和相位调制光纤传感器中,引入传感器、传感模型、复用和数据融合等四个层面的数据融合技术以分离时变耦合信号。     

Twisting and annealing optical fiber for current sensors

We demonstrate that twisting a fiber a few turns per meter before it is annealed largely eliminates the residual linear birefringence. This dramatically improves the yield of annealed coils used for current sensing and makes it possible to use fibers that previously had large residual linear birefringence. Twisting the fiber is effective because the residual birefringence, associated with core ellipticity, is reduced to near zero by twisting. A theoretical model of the twisted and annealed fiber current sensor is compared to experimental data. We also show good temperature stability for a sensor made with this new technique     

Current status of micro- and nano-structured optical fiber sensors

Recently developed micro- and nano-structured optical fiber sensors, with particular reference to surface plasmon resonance (SPR) fiber sensors and photonic crystal fiber (PCF) sensors are reviewed. SPR fiber sensors can have diverse structures such as D-shape, cladding-off, fiber tip or tapered fiber structures. Some of the recently developed novel structures include the use of various types of fiber gratings in SPR fiber sensors. PCF sensors cover diverse recent developments on photonic-bandgap fiber, holey fiber, hole-assisted fiber and Bragg fiber sensors. Major applications of these include gas sensors and bio-sensors. These micro- and nano-structured fiber sensors have attracted considerable research and development interest, because of their distinct advantages, which include high sensitivity, small sensor head footprint and the flexibility of the optical fibers. They are also of academic interest, and many novel ideas are continuously developed.     

Demodulated method of optical fiber stokes temperature sensors

The optical fiber temperature sensoris one of the dis-tributed measurement apparatus applied to the smartstructures of civil and military engineering.In the dis-tributedfiber Ramantemperature sensor ,the anti-Stokesand Stokes scattering radiation is sensi…