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为了实现单一光纤光栅对压强精确测量,设计了一种温度不敏感的光纤布拉格高压传感器。对该传感器的温度特性及压强响应特性进行研究。给出了该传感器的结构及封装方法。从理论上分析了该传感器的温度去敏原理,推导了该压强传感器的光纤布拉格光栅中心波长与压强的关系,得到了该传感器的压强响应灵敏度的解析表达。通过实验分析传感器的温度特性及压强响应。实验结果表明,在21℃~260.8℃的范围内,实现了温度补偿,平均波长漂移量为0.75 pm/℃,在0~44 MPa的范围内,获得了-0.054 8 nm/MPa的压强响应灵敏度,是裸光纤布拉格光栅压力响应灵敏度的18.27倍。该传感器的压强响应具有很好的线性和重复性,实验值与理论值吻合得很好,该传感器能够通过一只光纤布拉格光栅实现压强的精确测量。 相似文献
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Irradiation effect on strain sensitivity coefficient of strain sensing fiber Bragg gratings
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The effect of irradiation on the strain sensitivity coefficient of strain sensing fiber Bragg gratings(FBGs) has been investigated through experiments. FBGs were fabricated in single mode fibers with 3 mol% Ge-concentration in the core and with a H2-loading treatment. In experiments, the FBGs were subjected to γ-radiation exposures using a Co60 source at a dose-rate of 25 Gy/min up to a total dose of 10.5 kGy. The GeO defect in fiber absorbs photons to form a GeE’ defect; the interaction with H2 is a probable reason for the γ-radiation sensitivity of gratings written in hydrogen loaded fibres. The effect mechanism of radiation on the strain sensitivity coefficient is similar to that of radiation on the temperature sensitivity coefficient. Radiation affects the effective index neff, which results in the change of the thermo-optic coefficient and the strain-optic coefficient. Irradiation can change the strain sensitivity coefficient of FBGs by 1.48%–2.71%, as well as changing the Bragg wavelength shift(BWS) by 22 pm–25 pm under a total dose of 10.5 kGy. Our research demonstrates that the effect of irradiation on the strain sensitivity coefficient of FBG is small and that strain sensing FBGs can work well in the radiation environment. 相似文献
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光纤Bragg光栅应力传感中温度交叉敏感问题研究 总被引:3,自引:0,他引:3
针对光纤Bragg光栅应力传感中温度交叉敏感的问题,设计了一种有效的无源温度补偿方法和补偿结构。通过理论模拟,分析了M值不同时补偿效果曲线的变化,从中得到了补偿效果最好时的M值;得出了不同预应变情况下的温度特性曲线,从中找出了温度特性被完全补偿时的预应变的值;分析了温度补偿中出现过补偿和欠补偿现象的原因。通过该方法,有效地解决了光纤Bragg光栅传感中的温度交叉敏感问题。温度补偿后可以满足对光纤光栅温度稳定性要求较高的光纤传感、通信等领域的需要。 相似文献
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The temperature distribution and the thermal stress distribution of Bragg fiber laser are analyzed by solving thermal transfer equations. The changes of refractive index derived from the temperature and the thermal stress are discussed separately. Results indicate that the change of index refraction caused by temperature is larger than by thermal stress. 相似文献
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光纤布拉格光栅在通信和传感领域具有广泛的应用。利用光纤布拉格光栅中心波长的偏移,可以测量温度和应变等多种物理量,但必须解决光栅对温度和应变的交叉敏感问题。该文简要分析了光纤光栅作为传感器的基本原理及其优点,设计了利用参考光栅法分离温度影响以及利用掺铒光纤的自发发射放大特性分离温度影响的2种应变测量方法。最后,介绍了一种利用倾斜光纤光栅的主模和边模对布拉格光栅中心波长的偏移进行解调的方法,该方法成功地分离了温度对应变测量的影响。 相似文献
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光纤光栅传感技术在工程中的应用 总被引:3,自引:0,他引:3
综述了光纤光栅传感器近年来在工程结构健康监测、石油产业、电力行业、岩土工程、航空航天、采矿、爆破、交通及医学等各个领域的应用情况。文章认为,限制光纤光栅传感器产业化和大规模应用的主要因素是缺乏统一的设计理论和制作方法,这使得不同厂家生产的传感器规格存在差异。另外,由于复杂的生产技术和精细的生产过程使传感器生产成本较高,而且能实际应用的光纤光栅传感器的解调产品并不多,且价格很高。根据上述分析,文中对该项技术未来的发展方向提出了展望。 相似文献
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This study proposed the modeling of fiber Bragg grating as a sensor for the optimum reflectivity with minimum discontinuities at the end of center wavelength. Recent advancement in optical sensor technology, make it necessary to generate the optimum results with minimum error. In this analysis, dependence of grating output spectra on various parameters has been studied for minimum bandwidth, side lobes and maximum reflectivity. In previous studies effect of length and other parameters has been studied. In this paper author has included the effect of modulation depth also. Study shows that grating length and modulation depth of refractive index of core are very critical factors which significantly alter the grating characteristics. Here low absorption third window of optical communication is used for the sake of low attenuation. All the simulation has done using GratingMOd software using transfer matrix method. 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
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Based on the physical fact that a laser containing a gain medium with homogenous line broadening oscillates at the wavelength which requires the smallest threshold gain due to the mode competition effect, after taking into account the wavelength-depended reflectivity distribution profile of a fiber Bragg grating, the oscillation wavelength λl of fiber Bragg grating semiconductor lasers has been investigated theoretically. The results show that the laser oscillation wavelength λB is not fixed at the Bragg reflection wavelength λl of fiber Bragg grating, and the offset between λB and λl depends on the reflectivity distribution profile of fiber Bragg grating and the gain profile of semiconductor gain medium. 相似文献
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以耐高温光纤光栅和普通的光纤光栅为实验研究对象,研究了其高温特性。普通的FBG,当温度超过300℃以上,光纤光栅已变黑变脆,虽然有传感特性,但已不能在实际中应用;通过对耐高温光栅裸栅进行300℃以上的高温实验,发现耐高温FBG处于20℃~350℃之间时反射波长与温度之间有着良好的线性关系,且光栅性能良好,没有出现被碳化现象,灵敏度为0.01nm/MPa;随着温度进一步升高,FBG反射波长与温度开始呈现非线性关系。实验结果表明,耐高温光栅适合于高温油气井下应用。 相似文献
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差动式光纤Bragg光栅沉降仪 总被引:2,自引:2,他引:0
研制了一种测量地表沉降变形的差动式光纤Bragg光栅沉降仪。等强度悬臂梁的底部固定于工地上的固定平台,顶端通过刃口、挂钩和连杆与沉降墩连接。在该测量中,沉降仪将沉降墩的地沉降量转换为悬臂梁的挠度。悬臂梁作用粘贴于其上下表面的光纤Bragg光栅产生应变,即传感光栅的Bragg波长产生了移位。对粘贴在悬臂梁上、下表面的传感光栅的Bragg波长进行差动运算,实现温度补偿,减小人为和气候因素的影响。在挂钩和沉降敦之间采用了螺旋结构连接,可通过调整螺旋或更换不同长度的挂钩来调节传感器的测量范围。荷载实验表明,该沉降仪的测量精度为0.004mm,低于变形测量中的科研级测量精度0.01~0.05mm。 相似文献
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Sensing characteristics of Bragg grating imprinted in a three-mode elliptical core fiber were investigated in details. The grating sensitivity to temperature and to strain was measured for each polarization and spatial mode. The experimental results show very small difference in the grating sensitivity vs. mode order and polarization. We also modeled the sensitivity of the host elliptical core fiber to these two parameters. We demonstrated relatively good agreement between the sensitivity of the grating determined in our experiment and the calculated sensitivity of the host fiber for respective modes. 相似文献
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报道一种新颖的用于多波长光纤激光器的超结构光纤Bragg光栅(SFBG)梳状滤波器,其突出特点是仅由单个光栅构成、折射率调制和局部啁啾富于变化、反射峰均匀性好、窄带宽和标准的信道间隔.采用基于LP算法的IS光纤光栅设计技术,将整体加窗切趾法改进为各信道独立加窗切趾,成功地设计出所需的SFBG,同时对SFBG的制作技术也进行了探讨.用传输矩阵法分析反射谱、时延曲线和群时延抖动.结果表明,所设计的SFBG满足各项设计指标要求,在DWDM系统中,这种新颖的SFBG可望成为用于多波长光纤激光器的最理想的高性 能梳
关键词:
超结构光纤Bragg光栅
光栅设计
梳状滤波器 相似文献