Effects of hydrogen loading conditions on fabrication of long-period fiber-grating sensors by low-pressure mercury lamp
Effects of hydrogen loading conditions on fabrication of long-period fiber-grating sensors by low-pressure mercury lamp
复制标题
氢负载条件对低压汞灯制作长周期光纤光栅传感器的影响
DOI：
10.1117/12.2070925
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Yoshihisa Tashiro
中科院分区：
文献类型：
--
作者：
Toru Mizunami;Yoshihisa Tashiro
为了缩短低气压汞灯制作长周期光纤光栅传感器的曝光时间，研究了充氢条件。氢压升高135atm，曝光时间缩短至120atm的2/3。将加载时间从4周增加到12周，暴露时间缩短到相同压力的3/4，或120atm的一半，持续3周。在曝光过程中，纤维的温升被测量为16°C或更低。通过求解扩散方程的数值分析，研究了氢分子在纤维中的分布。分析的结果与测量的氢浓度和曝光时间的压力关系相吻合。对于较长的加载时间，计算和测量的氢浓度都没有增加：不能解释为什么较长的加载时间缩短了曝光时间。除了获得了周期为460μm的温度敏感和应变不敏感的长周期光栅外，其温度灵敏度和应变灵敏度均低于120atm下的载氢量。
Conditions of hydrogen loading were studied for shortening of the exposure time for fabrication of long-period fiber grating sensors using a low-pressure mercury lamp. By an increased hydrogen pressure of 135 atm, shortening of the exposure time to 2/3 that of 120 atm was obtained. By increasing the loading time from 4 to 12 weeks, the exposure time was shortened to 3/4 that of the same pressure, or half that of 120 atm for 3 weeks. The temperature rise of the fiber during exposure was measured to be 16 °C or less. Distribution of hydrogen molecules in the fiber was studied by a numerical analysis solving a diffusion equation. The result of the analysis agreed with the pressure dependence of the measured hydrogen concentration and the exposure time for fabrication. For the longer loading time, neither the calculated nor the measured hydrogen concentrations increased: the shortening of the exposure time by the longer loading time was not explained. The temperature and strain sensitivities were lower than those of hydrogen loading at 120 atm except that a temperature sensitive and strain insensitive long-period grating was obtained with a period of 460 μm.