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介绍了一种简单且灵敏度较高的Mach-Zehnder干涉湿度传感器.将单模光纤和多模光纤渐变熔接光纤锥,色散补偿光纤被熔接在两个多模渐变光纤之间,形成了单模光纤-光纤锥-多模渐变光纤-色散补偿光纤-多模渐变光纤-光纤锥-单模光纤结构的传感器.光纤锥起到了增加包层模能量的作用,两个多模渐变光纤节点作为光耦合器,从而形成光纤Mach-Zehnder干涉仪.外界环境湿度的变化,将使得传感器透射谱能量发生变化,通过测量干涉谱波峰峰值能量实现对湿度的测量.实验结果表明干涉谱波峰峰值能量与环境湿度之间存在良好的线性关系.当环境湿度在35%RH—85%RH范围内变化,一段由20 mm色散补偿光纤组成的传感器,其灵敏度为-0.0668 dB/%RH,相关度为0.995.该传感器结构紧凑、尺寸小、制造工艺简单,这使其可以被广泛用于湿度测量. 相似文献
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《Optik》2014,125(1):301-303
In this paper we report a simple microbend fiber optic sensor using a plastic fiber, LED and photodetector assembly for sensing minute variation of refractive index of chlorinated water. Chlorinated water has slightly higher refractive index and gradual release of chlorine from bleaching powder treated water causes a temporal decrease in refractive index of the solution. The evaporation of chlorine from water and the change in refractive index is found to follow a first order exponential decay function of time. Introducing microbends in an optical fiber is easier and less complex than etching of fiber cladding for traditional optical fiber sensors. 相似文献
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A new high-birefringence (Hi-Bi) fiber torsion sensor demodulated by a Hi-Bi fiber Bragg grating (FBG) is proposed in this study. The twisted Hi-Bi fiber sensor characteristics are analyzed using the Jones matrix. The intensity ratio from two reflected Bragg wavelengths is associated with the twist angle of the measured Hi-Bi fiber. It is found that the twist angle resolution is estimated at around 0.3° under ±0.1 dB readout from an optical spectrum analyzer if the polarization state of the light source is stable. The advantages of this new torsion sensor are: (1) insensitivity to intensity variations from the light source, (2) insensitivity to the torsion gauge length, and (3) absolute measurement in the twist angle. However, the polarization state of light in the proposed method needs to be controlled, and any birefringence change in the twisted Hi-Bi fiber needs to be prevented. 相似文献
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Jiangdong Deng Hai Xiao Wei Huo Ming Luo Russ May Anbo Wang Yilu Liu 《Optics & Laser Technology》2001,33(5):72
In this paper, a fiber optic acoustic sensor system is designed and tested for on-line detection of the partial discharges inside high voltage power transformers. The fiber optic sensor uses a silica diaphragm and a single mode optical fiber encapsulated in a silica glass tube to form an extrinsic Fabry–Perot interferometer. Test results indicate that the developed fiber optic sensors are capable of detecting the acoustic signals propagating inside the transformer oil with high resolution and high frequency. 相似文献
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《Current Applied Physics》2020,20(10):1103-1109
We demonstrate a highly efficient, broadband fiber-optic intermodal converter. The technique relies on a long period grating mechanically induced in a two-mode fiber. A compact, portable apparatus was designed and fabricated, where period-variable metallic corrugation is implemented to form periodic micro-bends along the fiber. The coupling strength between the interacting fiber modes and the grating period can be tuned continuously and individually using two control knobs in the apparatus. Experimental results show that the complete coupling between the LP01 and LP11 modes is achieved, which is confirmed by an observed over-coupling while increasing the grating strength. For the short fiber length of <1.9 cm (33 grating periods), large band-rejection of −32.5 dB was obtained at resonance. The band rejection efficiency over 98.6% have been achieved in the entire communication C-band. As the grating strength increased, two over-couplings were observed at resonance, which indicates the high efficiency of the device. Experimental results are confirmed by our numerical simulations. 相似文献
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聚合物封装的高灵敏度光纤光栅温度传感器及其低温特性 总被引:10,自引:0,他引:10
介绍了一种新型的光纤光栅温度传感器。这种光纤光栅温度传感器使用了特殊的工艺将光纤布拉格光栅封装于一种热膨胀系数较大的有机聚合物基底中 ,使得传感器的温度灵敏性比裸光纤光栅提高了 12 .3倍 ,其温度灵敏度系数KT 达到 82 .6 9× 10 -6/℃。在 - 80~ 0℃的低温度范围内 ,对这种新型光纤光栅温度传感器的反射谱进行了测量。研究了这种新型光纤光栅温度传感器的低温特性 ,并与裸光纤光栅和铝基封装的光纤光栅进行了比较 ,结果表明这种新型的光纤光栅温度传感器具有很好的低温响应特性。 相似文献
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A. B. Lobo Ribeiro J. L. Santos J. M. Baptista L. A. Ferreira F. M. Araú jo A. P. Leite 《Fiber and Integrated Optics》2005,24(3):171-199
A general overview of the R&D activity in fiber optic sensing developed over the last fifteen years in Portugal is given. Different topics are addressed, including interferometric, intensity and Bragg grating based fiber optic sensors, signal processing and multiplexing techniques, optical current sensors, together with some references to field trials and applications. Possible guidelines for present and future national R&D activity on this subject are outlined. 相似文献
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This paper describes a process that has been successful in generating a specification to guide the user community in the procurement of single-size, multimode optical fiber for on-premises applications. This process began with an attempt to adopt an industry standard as a federal standard that would eliminate a multiplicity of choices available from the marketplace. The initial EIA-458-A Standard contained four “preferred” sizes. Discussions both in a government standards committee and in an applications-oriented industry (EIA) working group indicated the desirability of recommending a single fiber size. The process by which the industry committee selected the 62.5-μm core diameter/125-μm cladding diameter multimode fiber is presented. The next element of the process was that of selecting the appropriate standard performance measures and attributes that would assure minimum performance of graded parameters such as attenuation and bandwidth, as well as a uniform specification of the product. The vehicle selected for this specification was the EIA 492-Series Generic, Sectional, and Blank Detail Specifications. Inputs were solicited from all of the identified U.S. manufacturers of this fiber size. Those inputs were coordinated and integrated into a detail specification, which is now being circulated by the EIA on a standards proposal ballot. After ballot approval, it will be published as an ANSIIEIA standard specification. Similar work has been initiated to develop a detail specification for fiber optic cables based on a related set (472-Series) of EIA specifications. The process of developing a detail specification that assures conformance of the product to dimensional and strength tolerances as well as performance measures requires considerable coordination and iteration. No proprietary information or processes are contained in the specification so that the industry participants are free to compete on price and performance as long as compliance with the specification can be demonstrated. 相似文献
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The paper deals with a fiber optic evanescent field absorption sensor that can be used for the detection of chlorine content in drinking water. The technique is based on the absorption of evanescent fields through the development of color owing to the reaction of an organic compound diethyl phenylene diamine with chlorine, which is already present in water. In the experiment, a U-shaped optical sensor probe is used because the sensitivity of the system improves due to the higher penetration depth achieved in this case. The improvement in sensitivity (in the case of U-shaped probed) is also shown experimentally. 相似文献
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A. B. LOBO RIBEIRO J. L. SANTOS J. M. BAPTISTA L. A. FERREIRA F. M. ARAÚJO A. P. LEITE 《Fiber and Integrated Optics》2013,32(3-4):171-199
Abstract A general overview of the R&D activity in fiber optic sensing developed over the last fifteen years in Portugal is given. Different topics are addressed, including interferometric, intensity and Bragg grating based fiber optic sensors, signal processing and multiplexing techniques, optical current sensors, together with some references to field trials and applications. Possible guidelines for present and future national R&D activity on this subject are outlined. 相似文献
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四端光纤补偿网络的理论分析 总被引:1,自引:0,他引:1
强度干扰是阻碍强度调制光纤传感器发展及应用的关键问题.研究表明,光纤网络补偿方法对抑制强度干扰是一种行之有效的方法.作者经过深入的研究,提出了一种先进的四端光纤补偿网络结构.本文对四端光纤补偿网络进行了全面、系统的分析,揭示了网络的特性.这对于强度调制光纤传感器的发展及应用具有重要的意义.同时,对于强度调制光学测量系统也具有一定的意义. 相似文献
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光纤传感器在线检测耐火砖厚度的研究 总被引:1,自引:0,他引:1
本文详细论述了光纤在线砖厚传感器的原理,阐述了砖厚偏差量的光纤测量方法以及光纤砖厚传感器的研制。并讨论了用V/F转换器实现A/D转换和单片机智能系统的设计特点。 相似文献
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A sensing fiber, with a gradually increasing Raman-gain-coefficient (gR/Aeff)along the fiber length, and which can keep the received Raman Stokes power constant in a distributed Raman-based Fiber-optic temperature Sensor, is proposed. This method can be an additional and easy way to further extend the sensing distance of the distributed Raman Fiber-optic temperature Sensor. 相似文献
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Aïssa Harhira Francis Guay Maxime Daigle Raman Kashyap 《Optics Communications》2010,283(23):4633-4638
A new holographic technique is proposed for fabricating long-period fiber gratings (LPGs) using a CO2-laser and a phase mask. A CO2 laser operating at 10.6 μm is incident normally on the phase mask and the diffracted interfering beams imprint a thermally induced periodic modulation into the cladding of the fiber placed behind the mask. Preliminary results of this technique are presented and discussed. An unusual self-tapered fiber LPG (STFLPG) is also presented. 相似文献