共查询到17条相似文献,搜索用时 93 毫秒
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《物理学报》2019,(24)
锥形结构的光纤光栅具有对应力敏感而对温度不敏感的特性,这可以有效抑制温度与应力的交叉敏感问题.提出一种利用熔融拉锥技术实现对称双锥形结构的光纤光栅,结合传输矩阵法建立其传感特性理论模型并加以分析.首先研究影响啁啾系数变化的因素,得到啁啾系数与光栅长度变化量的关系;其次对对称熔融拉锥型光纤光栅的光谱特性进行分析,讨论光谱短波长处出现密集调制现象的成因;然后仿真研究温度和应力对对称熔融拉锥型光纤光栅的反射谱影响,得到对应的中心波长和光谱宽度的变化关系.并针对应力灵敏度较低问题,提出聚合物涂覆锥区增大传感锥区光纤半径差而进行增敏的方案,利用熔融拉锥法制备对称熔融型光纤光栅,通过实验验证理论仿真的正确性,对称熔融拉锥型光纤光栅应力灵敏度为0.11391 nm/N.研究表明,对称熔融拉锥型光纤光栅的啁啾系数与光栅长度变化量满足线性关系.对称熔融拉锥型光纤光栅端处光栅周期较小,且反射率小于1,左边透射光与右边反射光会产生干涉,因此光谱短波长处会出现密集调制现象.随着轴向应力的增大,光栅反射中心波长向长波方向移动,光谱宽度变大,且两者与轴向应力均满足线性关系;随着温度升高,反射谱峰中心波长向长波方向移动,满足线性关系,而温度对光谱宽度的影响可忽略不计.通过增大传感锥区光纤光栅半径差,光纤光栅的应力灵敏度较之前提高了数百倍,并且增大光栅长度变化量有助于进一步提高应力灵敏度.对称熔融拉锥型光纤光栅的光谱宽度只对应力敏感而对温度不敏感,这一特性可用于实现温度与应力双参量测量. 相似文献
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通过电弧放电在光子晶体光纤(PCF)中产生空气孔塌缩来刻入长周期光栅(LPG)。在此基础上进一步分析其周期长度、周期个数、环境折射率和温度对该光栅传输特性的影响。研究结果表明,该方法制备的光栅的传输特性随周期长度和周期个数有规律地变化,并测得其环境折射率灵敏度系数和温度灵敏度系数分别为420nm/RIU(RIU表示折射率单位)和7.86pm/℃。由此可见,这种光栅具有对环境折射率的变化敏感而对温度的变化较不敏感的特性,因而在减少交叉敏感的光纤传感器件方面有广泛的应用前景。 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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熊猫型保偏光纤光栅温度和压力传感特性的实验研究 总被引:1,自引:1,他引:1
对熊猫型保偏光纤光栅的传感特性进行了深入的实验研究,采用温箱和压力罐分别进行了温度和压力传感特性的实验研究.实验结果表明:在0~2.5 MPa的压强范围内,熊猫型保偏光纤光栅两个偏振方向上的压力敏感系数分别为0.004 88 nm/MPa和0.003 52 nm/MPa;在15~50 ℃的温度范围内,两个偏振方向上的温度敏感系数为0.01018 nm/℃和0.008 8 nm/℃.该光纤光栅两偏振态对温度和压力的不同敏感特性可用于解决光纤光栅的交叉敏感问题. 相似文献
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基于长周期光纤光栅嵌入型Sagnac环光谱的折射率测量 总被引:1,自引:0,他引:1
将长周期光纤光栅(LPG)和光纤Sagnac环相结合,实现了折射率和温度的同时测量.首先利用二氧化碳激光器在保偏光纤上制作了长周期光纤光栅(PM-LPG),然后把该PM-LPG和普通单模光纤耦合器组成Sagnac环,作为传感单元.实验选择其某一透射峰作为测试对象,其波长随温度变化,强度随折射率变化,因此可实现两个参量的... 相似文献
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Fiber grating sensors for high-temperature measurement 总被引:1,自引:0,他引:1
Yage Zhan Hua Wu Qinyu Yang Shiqing Xiang Hong He 《Optics and Lasers in Engineering》2008,46(4):349-354
Two fiber grating sensors for high-temperature measurements are proposed and experimentally demonstrated. The interrogation technologies of the sensor systems are all simple, low cost but effective. In the first sensor system, the sensor head is comprised of one fiber Bragg grating (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 based on the wavelength-shifts of the FBG induced by the strain. In the second sensor system, a long-period fiber grating (LPG) is used as the high-temperature sensor head. The LPG is very-high-temperature stable CO2-laser-induced grating and has a linear function of wavelength–temperature in the range of 0–800 °C. A dynamic range of 0–800 °C and a resolution of 1 °C have been obtained by either the first or the second sensor system. The experimental results agree with theoretical analyses. 相似文献
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An alternative all-fiber sensor for simultaneous strain and temperature measurement based on a photonic crystal fiber (PCF) spliced between single-mode fibers cascaded with a long period grating (LPG) is proposed. By collapsing the air holes at two splicing regions along the PCF, a simple but effective modal-interference (MI) is occurred between the core and cladding modes of the PCF. Due to the different responses on the changes of strain and temperature on the MI and the cascaded LPG, the strain and temperature can be measured simultaneously. Experimental results show that the sensing resolution of 9.1 με in strain measurement is experimentally achieved over a range of 2640 με, while the temperature sensing resolution is 0.27 °C within a range of 30-100 °C. 相似文献
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Chun-Liu Zhao Jiarong Zhao Wei Jin Jian Ju L. Cheng Xuguang Huang 《Optics Communications》2009,282(20):4077-4080
We present a new design for simultaneous strain and temperature measurement using a high-birefringence fiber loop mirror (HiBi-FLM) concatenated with a temperature-insensitive long-period grating (LPG) written in a photonic crystal fiber (PCF). The FLM acts as a sensor head, while the LPG in PCF serves as a filter to convert wavelength variation to optical power change. By measuring the wavelength variation and the power difference of two near peaks in the spectral response of this configuration, simultaneous strain and temperature measurement is obtained. 相似文献
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A Sagnac interferometer with a long-period fiber grating (LPG) inscribed in the polarization-maintaining fiber (PMF) is proposed and experimentally demonstrated for simultaneous measurement of strain and temperature. Due to the different responses of the LPG and the Sagnac interferometer to strain and temperature, simultaneous measurement can be achieved by monitoring the wavelength shifts and the intensity changes of a resonance dip of the sensor setup. The experimental results show that the achieved sensitivities to strain and temperature are 6.4 × 10− 3 dB/με and 0.65 nm/°C, respectively. 相似文献
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报道了一种基于掺铒光纤激光器瞬态特性的新型应变传感系统.用光纤环反射镜和光纤Bragg光栅(FBG)构成Fabry-Perot线型腔.腔内插入一个长周期光纤光栅(LPG),其透射谱的中心波长为1574.4nm.FBG的带宽为0.23nm,不受力时其反射波长为1557.98nm,位于LPG的透射谱左沿;当FBG受力时激射波长向长波方向移动,激光通过LPG时透射损耗增大,腔损耗的增加将使激光激射延迟时间增加.因此,应变的大小可以通过激光产生的延迟时间来测量.这种新型应变传感器的分辨率和灵敏度由抽运光脉冲的高、
关键词:
应变传感
光纤激光器
时域测量
光纤Bragg光栅 相似文献