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为解决干涉型光纤应变传感器自由光谱范围较小或干涉条纹精细度较低等问题,提出了一种基于单拉锥光纤布拉格光栅的法布里-珀罗腔的应变传感结构及其改进方案。利用啁啾光纤布拉格光栅不同位置反射不同波长的特性,形成腔长随波长连续变化的法布里-珀罗腔,得到了无穷大的自由光谱范围且谐振谷精细度高。数值计算结果表明,应变传感灵敏度与拉锥光纤的腰区直径和栅区长度正相关。在0~300 με范围内,当腰区直径为光纤直径的3/25,栅区长度为30 mm时,应变传感灵敏度为7.05 pm/με。该结果对其他干涉型传感结构的设计具有一定的参考价值。 相似文献
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双套管式光纤Bragg光栅温度传感器 总被引:3,自引:0,他引:3
研制了一种双套管式光纤Bragg光栅温度传感器,以实现无外力作用的温度测量。其中外套管隔离外加应力应变,在内套管内松弛地放置光栅以隔离封装结构的表观热应变。引入引出尾纤穿过带孔螺栓,以探测多个串联光栅。为了避免光栅处于张拉状态,封装在外套管1、外套管2和内套管中的光纤余长应分别大于1.4mm,1.8mm和0.4mm。试验结果表明,该光栅传感器的温度响应灵敏度为9.671×10-3nm/℃,温度测量分辨率为0.1℃。当水温从20℃跃变到70℃时,该传感器的温度响应时间分别为t0.5=15±2s和t0.9=52±4s。当水温从70℃跃变到20℃时,该传感器的温度响应时间分别为t0.5=26±9s和t0.9=63±8s。 相似文献
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At cryogenic temperature, a fiber Bragg grating (FBG) temperature sensor with controllable sensitivity and variable measurement range is demonstrated by using bimetal configuration. In experiments, sensitivities of -51.2, -86.4, and -520 pm/K are achieved by varying the lengths of the metals. Measurement ranges of 293 - 290.5, 283 - 280.5, and 259 - 256.5 K are achieved by shortening the distance of the gap among the metals. 相似文献
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A temperature distribution sensing system based on the reflection spectrum of a 70 mm apodized chirped fiber Bragg grating has been demonstrated. Reflection variations created by the Fabry-Perot effect due to the intra-grating wavelength shift are presented. By fitting a parametric transfer matrix model of the grating response to measured spectra, the temperature change, position and width of a localized temperature change are obtained. This system is particularly attractive of its simplicity, high spatial resolution and ability in measuring a non-monotonic distribution. Experiments to measure two localized heating regions along the grating indicate that the technique is promising for measuring more complex temperature profiles. 相似文献
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A high sensitive fiber Bragg grating (FBG) strain sensor with automatic temperature compensation is demonstrated. FBG is axially linked with a stick and their free ends are fixed to the measured object. When the measured strain changes, the stick does not change in length, but the FBG does. When the temperature changes, the stick changes in length to pull the FBG to realize temperature compensation. In experiments, 1.45 times strain sensitivity of bare FBG with temperature compensation of less than 0.1 nm Bragg wavelength drift over 100 ℃ shift is achieved. 相似文献
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A four-element fiber Bragg grating acceleration sensor array is presented in this paper. The system combines an unbalanced Mach–Zehnder interferometer and three coarse wavelength division multiplexers (WDMs). The totally passive scheme has the advantages of high operation frequency and loose requirements for the working environment. An acceleration resolution of better than for the four channels is achieved. 相似文献
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A novel fiber Bragg grating high-temperature sensor 总被引:3,自引:0,他引:3
A novel fiber Bragg grating (FBG) sensor for the measurement of high temperature is proposed and experimentally demonstrated. The interrogation system of the sensor system is simple, low cost but effective. The sensor head is comprised of one FBG and two metal rods. The lengths of the rods are different from each other. The coefficients of thermal expansion of the rods are also different from each other. The FBG will be strained by the sensor head when the temperature to be measured changes. The temperature is measured basis of the wavelength shifts of the FBG induced by strain. A dynamic range of 0–800 °C and a resolution of 1 °C have been obtained by the sensor system. The experiment results agree with theoretical analyses. 相似文献
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A novel single-longitudinal-mode (SLM) erbium-doped fiber laser with a simple linear cavity based on a fiber Bragg grating Fabry-Perot filter (FBG-FPF) and a narrowband (~0.06 nm) FBG is proposed and demonstrated experimentally. Two uniform FBGs form the FBG-FPF, which has two ultranarrow transmission bands with a bandwidth of 0.12 pm and a wavelength spacing of 0.095 nm. By slightly tuning the central wavelength of the narrowband FBG, SLM lasing at 1549.658 or 1549.563 nm (corresponding to the two transmission peaks of the FBG-FPF) is achieved with a laser output power of ~4 mW, when the pump power is ~75 mW. 相似文献
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介绍了FBG(光纤布拉格光栅)温度传感器测温的基本原理和封装方法,提出一种新型的FBG温度传感器的封装技术,包括封装结构的设计及封装材料的合理选择,目的是提高FBG的温度敏感系数和消除应力的交叉影响。通过对裸光纤和封装后FBG温度传感器的温度特性、应力影响等进行对比实验研究,在5℃至90℃温度范围对FBG的反射波长进行了测量,结果表明:采用此法封装后的FBG温度传感器对温度具有很好的线性度和重复性,基本上消除了应力的影响,可以准确监测温度,测温范围为-15℃~200℃,精度达到±0.05℃。 相似文献
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A new type fiber bending sensor based on a tilted fiber Bragg grating (TFBG) interacting with a multimode fiber (MMF) is presented. The sensing head is formed by insertion of a small section of MMF between a single-mode fiber (SMF) and the TFBG. The average reflective power in the cladding modes decreases with the increase of curvature. The measurement range of the curvature from 0 to 2.5 m−1 with a measurement sensitivity of −802.4 nW/m−1 is achieved. The proposed sensor is also proved as temperature-independent from the experimental investigation. 相似文献
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The study on fiber Bragg grating (FBG) displacement sensor based on monitoring the back-reflected power from an array of novelly embedded FBG sensors is presented. The sensor is a uniform FBG with three sections that are embedded in different layer in a composite lamina. Its bandwidth is displacement dependent and hence its reflected power varies almost linearly with displacement and it is insensitive to temperature variation. Thus, only low-cost photodetector (PD) is required to monitor displacement. This study demonstrates a novel fiber sensor, a method of fabricated the same, and a method to achieve simultaneous multi-sensor measurement. 相似文献
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Based on the effect of fiber Bragg grating (FBG) pressure difference sensitivity enhancement by encapsulating the FBG with uniform strength beam and metal bellows, a FBG pressure difference sensor is proposed, and its mechanism is also discussed. The relationship between Bragg wavelength and the pressure difference is derived, and the expression of the pressure difference sensitivity coefficient is also given. It is indicated that there is good linear relation between the Bragg wavelength shift and the pressure difference of the sensor. The theoretical and experimental pressure difference sensitivity coefficients are 38.67 and 37.6 nm/MPa, which are 12890 and 12533 times of that of the bare FBG, respectively. The pressure difference sensitivity and dynamic range can be easily changed by changing the size, Young's modulus, and Poisson's ratio of the beam and the bellows. 相似文献
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To test whether the fiber Bragg grating (FBG) sensor can endure the steady-state inertial loads caused by the acceleration and the sensing properties during the loads, a FBG strain and temperature sensor with aluminium alloy substrate package was designed, and the acceleration performance on the sensor was tested. The sizes of FBG strain and temperature sensor were designed and its package process was described. The strain and temperature sensing mechanisms of FBG sensor were analyzed, and the spectrum detection and demodulation system based on volume phase grating and linear array photodetector was developed. Finally, the acceleration test equipment was established, and the acceleration performance test of the selected FBG strain and temperature sensor was carried out in accordance with the requirements and methods of GJB150.15A acceleration test. The experimental results show that in the 2 min performance test before and after the acceleration test, the wavelength offset is below to ±50 pm, and the change of light intensity is below to 0.3 V. In acceleration test, the maximum fluctuation of wavelength offset is ±7 pm, and the light intensity is in the range of 1.3 V~4.003 V. It is proved that the designed FBG sensor has the ability to endure the acceleration loads and has the good sensing performance during the acceleration loads. Copyright ©2022 Journal of Applied Optics. All rights reserved. 相似文献
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High sensitivity fiber Bragg grating pressure difference sensor 总被引:6,自引:0,他引:6
Based on the effect of fiber Bragg grating (FBG) pressure difference sensitivity enhancement by encapsulating the FBG with uniform strength beam and metal bellows, a FBG pressure difference sensor is proposed, and its mechanism is also discussed. The relationship between Bragg wavelength and the pressure difference is derived, and the expression of the pressure difference sensitivity coefficient is also given. It is indicated that there is good linear relation between the Bragg wavelength shift and the pressure difference of the sensor. The theoretical and experimental pressure difference sensitivity coefficients are 38.67 and 37.6 nm/MPa, which are 12890 and 12533 times of that of the bare FBG, respectively. The pressure difference sensitivity and dynamic range can be easily changed by changing the size, Young's modulus, and Poisson's ratio of the beam and the bellows. 相似文献
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传送带类问题归类分析 总被引:1,自引:0,他引:1
本文中的传送带类问题是指以皮带传送装置(传送带)为载体而构建的各类物理问题.传送带类问题丰富多彩,能够很好地再现物理知识和考查各种能力,因而值得我们分类探究. 相似文献