法布里-珀罗薄膜干涉的光纤温度传感器

为了研制结构简单、成本低、可批量生产的微型光纤温度传感器,分析了薄膜干涉型光纤温度传感器的原理,选用ZrO2和Al2O3两种介质薄膜材料,采用TFCalc膜系设计软件设计了薄膜干涉型光纤温度敏感探头的膜系,由南光ZZS1100-8/G箱式真空镀膜系统采用电子束蒸发技术在普通多模光纤端面蒸镀介质薄膜,形成法布里-珀罗（Fabry-Perot）薄膜干涉,并搭建光纤温度传感测试系统,测试结果表明:在200~600℃范围内,所设计的干涉型光纤温度传感器的测试光谱随温度变化产生一定的波长漂移,且波长漂移的温度特性为线性,线性相关系数为99.7%,灵敏度为8.3710-6/℃。基于法布里-珀罗干涉的薄膜型光纤温度传感器体积小,成本低,结构紧凑,可批量生产,适合安装位置狭小或对传感器集成化要求较高的场合。     

一种使用光纤传感器的全光网络攻击检测研究

全光网络是通信网络发展的大趋势,光纤传感器因其所特有的特性具有电子传感器所无法比拟的优势。介绍了全光网络的结构和对全光网络可能采取的攻击方式,讨论了如何利用光纤传感器对针对全光网络的攻击进行检测。     

Temperature sensor based on dielectric optical microresonator

An optical temperature sensor has been presented based on Whispering Gallery Mode (WGM) dielectric microresonator. The effect of Transverse Electric (TE) wave propagation in dielectric micro-spheres presented has been for optical resonances based on WGM. TE waves are characterized both theoretically and experimentally for large size parameter of the micro-spheres. A theoretical model has been developed based on asymptotic approach. The theoretical development is mathematically robust and significantly less complicated than existing approaches presented in the literature. The quality factor of experimental resonance spectra observed in the laboratory is calculated approximately in the order of 10⁴ which is sensitive enough to detect micro or nano level temperature changes in the surrounding medium. The sensitivity of the Morphology Dependent Resonance (MDR) temperature sensor is wavelength change of 10⁻⁹ m for one degree centigrade change in temperature. This sensor could potentially be used for nano technology, Micro-Electro-Mechanical Systems (MEMS) devices, and biomedical applications.     

Research on SFTS structure based optical fiber sensor

A single-mode-few-mode-thin-core-single-mode (SFTS) structure based optical fiber sensor is fabricated and experimentally studied. The sensing principle relies on the inter-modal interference. Since the core diameter of few-mode fiber (FMF) is larger than that of single-mode fiber (SMF), the FMF helps to allow more light to enter the cladding of thin-core fiber (TCF), which helps TCF to excite cladding modes. The interference between core and cladding modes in TCF occurs at the joint of lead-out SMF and TCF. Experimental results demonstrate a refractive index (RI) sensitivity of ?103.34 nm/RIU and a temperature sensitivity of 0.05 nm/°C. The proposed sensor not only can measure temperature, but also can measure RI. In addition, the proposed sensor is simple for without complicated fabrication process.     

Water sensor with optical fiber

In optical-fiber networks, it is important to monitor water which seeps into splice enclosures. The fibers have residual stress at splicing points, and when water is present, this adversely affects fiber lifetime. A water sensor which has a simple structure for monitoring water at splicing points has been developed. This water sensor causes optical loss due to fiber bending when water seeps into splicing enclosures. The design method using a fiber-bending model and sensor performance are described     

Optical hydrogen sensor based on etched fiber Bragg grating sputtered with Pd/Ag composite film

A novel fiber optical fiber hydrogen sensor based on etched fiber Bragg grating coated with Pd/Ag composite film is proposed in this paper. Pd/Ag composite films were deposited on the side-face of etched fiber Bragg grating (FBG) as sensing elements by magnetron sputtering process. The atomic ratio of the two metals in Pd/Ag composite film is controlled at Pd:Ag = 76:24. Compared to standard FBG coated with same hydrogen sensitive film, etched FBG can significantly increase the sensor’s sensitivity. When hydrogen concentrations are 4% in volume percentage, the wavelength shifts of FBG-125 μm, FBG-38 μm and FBG-20.6 μm are 8, 23 and 40 pm respectively. The experimental results show the sensor’s hydrogen response is reversible, and the hydrogen sensor has great potential in hydrogen’s measurement.     

基于弯曲损耗的光纤温度传感器

为了推导多模光纤弯曲损耗与弯曲半径、环境温度的关系,采用了WKB法求解非均匀直光纤的传播模数,并将弯曲光纤的有效折射率、弯曲光纤截止传播常数和光纤的热光效应同时引入到非均匀直光纤有效传播模数中。利用多模光纤进行实验验证,研制出测温灵敏度为0.1/℃、测温范围为10℃～70℃的光纤温度传感器。结果表明,弯曲损耗随弯曲半径的增大而减小,随环境温度的升高而减小,可以利用弯曲损耗测量环境温度。     

基于F-P的光纤气体检测系统

简单介绍了利用F-P的可调谐性提出的一种新型的基于1550nm宽带光源的光纤气体检测系统的工作原理、实验装置软硬件设计以及利用该实验装置进行实验数据处理的思想--FFT一次谐波算法和计算光谱面积的算法.利用一次谐波的方法进行了实验,得出实验结果和结论.     

高双折射单模光纤温度传感器

1 引言 偏振干涉型光纤温度计的灵敏度介于干涉型和强度型之间。典型的干涉型光纤温度传感器是以光纤耦合器为核心,构成Mach-Zehnder的一类干涉仪,它是以两根光纤分别作为干涉仪的测量臂和参考臂。虽然灵敏度高,但由于外界环境因素对参考臂的干扰极为敏感,以致在一般条件下,难以正常工作。文献[2]则以一根高双折射光纤中正交偏振模HE_(11)对外界因素有不同相移,使这两个模式的光发生干涉,从而能有效地克服外界因素的干扰。本文利用时间相     

基于梳状滤波器的光纤甲烷传感器的研究

采用基于Sagnac的保偏光子晶体光纤(polarization-maintaining photonic crystal fiber,PM-PCF)滤波器,将宽带光源精确匹配甲烷气体在近红外波段的几个吸收线谱.设计出一个简单合理的多反射气室,使得光源和甲烷气体之间能够充分相互作用,提高了系统的灵敏度.同时,在测量甲烷气体浓度时,加入乙炔气体作为干扰,通过实验验证了该方案能够有效减缓交叉气体的灵敏度.     

Analysis of a damage sensor based on elastic-plastic metal coatingson optical fibers

Optical-fiber sensors coated with linear work hardening elastic-plastic materials are analytically explored to determine the effects the coating properties have on the sensor performance. The optical-fiber system is analytically subjected to both an axial load and a uniform thermal gradient. The nonlinear analysis reveals a mechanism for designing coatings which provide a memory to the optical-fiber sensor by undergoing permanent deformations in response to large thermal or mechanical strain excursions. This behavior is exploited to design a damage sensor     

基于DoE的BOTDR光纤传感器测温性能优化

通过理论和仿真结果研究基于自发布里渊散射的BOTDR(布里渊光时域反射仪)光纤传感器在测温方面的应用.借助于BOTDR传感器仿真模型阐述SBS阈值功率各种传统定义以及与测温精度有关的新定义.SBS阈值受多种相互作用的因子影响,使用DoE(实验设计)方法来优化仿真实验策略和获得最佳传感器配置参数,经DoE优化配置后,SBS阈值可达8.5dBm,探测距离最大可达110km.     

基于分布式光纤温度传感的煤层气井测试

分布式温度传感(Distributed Temperature Sensing,DTS)技术是一种实时监测被测环境温度场的新型传感技术,较于传统的井温测量技术,具有无源工作、分布采集、布设简单等优势。煤层气井的开采对井下的剖面温度和产层流量都有着明确的计量需求。本文简要介绍DTS设备和产量解释的原理,结合DTS设备在国内某煤层气井的实际温度监测试验,验证了DTS在生产测井温度监测方面的可行性,并通过解释软件初步测算煤层气井产层流量。通过与传统的测试方式对比,目前分布式温度传感的测温精度和分辨率分别达到1℃和0.1℃,产层流量计算误差控制在大约3%的水平。     

基于光学游标效应增敏的光纤湿度传感器

由于传统的湿度传感器测量湿度的准确性和稳定性易受环境影响,提出一种基于光学游标效应增敏的光纤湿度传感器,通过在单模光纤的尾端依次熔接一小段空芯毛细管和单模光纤,获得2个级联的光学法布里-珀罗(F-P)干涉仪,调整腔长使二者干涉谱的自由光谱范围接近,从而通过光学游标效应获取更高的湿度灵敏度,对湿度的响应由涂覆在光纤传感头...     

基于荧光猝灭原理的光纤溶解O2传感特性研究

采用荧光猝灭法检测溶解O2浓度。以邻菲咯啉钌作为荧光指示剂,用溶胶-凝胶法制备含有荧光指示剂的敏感材料,采用塑料光纤作为传感和传光元件,传感头做成U型以提高灵敏度,采用相移法实现对荧光寿命的测定。通过实验得出,溶解O2浓度在10mg/L以下时,荧光指示剂的荧光寿命与溶解O2浓度呈线性关系,实验测得该传感器的检测下限是0.36mg/L,系统的灵敏度为0.02mg/L。     

基于光纤内双开口F-P干涉腔的折射率传感器

为了实现高灵敏度液体折射率传感器的高效制备,采用飞秒激光直写技术,在光纤末端刻蚀出矩形凹槽,辅以光纤熔接方法,制备出一种基于光纤内双开口法布里-珀罗(F-P)干涉腔的折射率传感器。该传感器的液体折射率传感灵敏度达到1107.76nm/RIU。讨论了温度对该传感器性能的影响,温度串扰小于0.0025nm/℃;基于海水含盐浓度与折射率的线性关系,探讨了该传感器在海水含盐浓度传感测量方面的应用,灵敏度为0.171nm/(mgmL-1)。结果表明,基于光纤内双开口F-P干涉腔的折射率传感器具有干涉谱对比度高、线性响应良好、灵敏度高、不易受温度串扰、结构紧凑、制备简单高效等优点,在生物、医疗、化学、环境等领域中有着广泛的应用前景。     

Experimental study on optical fiber bundle hydrogen sensor based on palladium-silver optical thin film

In this paper, a 20 nm palladium-silver (Pd/Ag) ultrathin optical film is used for hydrogen gas sensing. The mole ratio of the two metals is controlled at Pd:Ag=3:1. In the direct current (DC) sputtering machine, the optical thin film is evaporated on the optical glass. Compared with pure palladium, the Pd/Ag alloy can increase the life and the stability of the sensing film. Optimum sputtering parameters for Pd/Ag alloy are presented in this paper, and the effects of different experimental conditions for hydrogen sensor are investigated, including the temperature effect, humidity effect and cross sensitivity of hydrogen sensor for different gases. The experiment results indicate that the hydrogen sensor based on Pd/Ag optical thin film exhibits good sensing characteristics. The existing of CO and water in hydrogen increases the response time and decreases the response amplitude of optical fiber bundle hydrogen sensor. The experiment results show that the increasing temperature can eliminate the effect and shorten hydrogen sensor response time effectively.     

光纤多参数传感器研究

基于光纤Bragg光栅(FBG)检测原理,研发了适用于地下空间安全监测应用的光纤风速、温度、湿度等多参数传感器。光纤风速传感器基于激光致热光纤热线式流量检测原理,对于低风速有较高的灵敏度,风速从0变化到0.5 m/s时,FBG波长变化量为800 pm,采用解调精度为1 pm的光纤光栅解调仪,风速分辨率为0.7 mm/s。光纤湿度传感器通过在FBG光栅表面均匀涂覆湿度敏感的聚酰亚胺溶液,湿度变化导致光纤应变变化进而实现湿度测量。对新型光纤光栅温湿度传感器的性能参数进行测试,实验测试结果显示,传感器监测灵敏度为4.2pm/%RH,检测精度小于±3%RH。     

Influence of metal layer on the transmitted spectra of SPR-based optical fiber sensor

For the surface plasmon resonance (SPR)-based optical fiber sensor with four-layer configuration (fiber core/metal/sensing layer/sample), the effects of different metals, different models (Lorentz-Drude model and Drude model) for the same metal, the thickness of metal layer, and the refractive index (RI) of sample on the transmitted spectra are investigated. The calculated results show that the real part of the refractive index of metal layer has the greatest effects on the sharp degree of the transmitted dip. Moreover, the dispersion function under four-layer configuration can be used to understand the relationship between the resonance wavelength and the thickness of metal layer.