In order to achieve long-distance, large-scale, real time temperature monitoring, temperature detection system was designed based on chirped fiber Bragg grating for more FBG sensor integrated on a single optical fiber. The functional relationship of Raster size, chirp factor and grating period was calculated. Modulation mode and modulation range was designed. In the experiment, the system was composed of a broadband light source, fiber optic, coupler, FBG detector and F-P demodulator, and so on. Its modulation range was 1530.0-1550.0nm. The temperature was tested by system within 15℃-55℃. Temperature results were compared with WR-220 type temperature detector. The results show that the temperature test results were basically the same by the uniformity FBG and chirped FBG, and its accuracy can meet the design requirements. However, the echo bandwidth was wider, and modulation capability was stronger by the system using chirped FBG. In a single fiber, the amount of loaded FBG detectors can be more than three times to which of uniform type FBG system. The design of system can significantly improve the ability of temperature detection without additional hardware, which has a good practicability.%为了实现长距离、大范围的温度在线监测,设计了基于啁啾调制技术的光纤布拉格光栅温度监测系统.采用线性啁啾结构获得更大回波带宽,从而在单根光纤上集成更多的FBG探测器.计算了光栅尺寸、啁啾系数与光栅周期的函数关系,设计了调制方式及范围.实验由宽带光源、光纤及耦合器、FBG探测器及F-P解调仪组成,调制范围为1530.0~1550.0 nm.对15℃~55℃内温度进行测试,测温结果与WR-220型温度探测器作对比,结果显示,均匀型FBG与啁啾型FBG的温度检测结果基本一致,精度均满足设计要求.但采用啁啾型FBG的系统回波带宽大,可调制能力强,单根光纤上可载入FBG探测器数量是均匀型FBG系统的3倍以上.该结构在不增加硬件的基础上提高了系统的测温能力,具有很好的实用性.
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