基于BOTDA技术的分布式光纤温度传感试验系统

摘要

The distributed temperature sensing system was established which consisted of a 150 mW narrow band laser, a 50 mW narrow band laser, an acousto-optic modulator, a pulse generator, an optical cireulator, a frequency counter, photo-detectors and corresponding optical apparatus,etc. The temperature sensing experiment was performed, and the Brillouin frequency shift spectrums of 25 ℃ , 35℃ , 45℃and 55 ℃ was achieved. The system' s temperature coefficient was got by fitting the peak values of frequency shift spectrums under different temperatures. The distributed temperature sensing experiment of fiber optic was confirmed. The sensing fiber was divided into 3 parts and the center part was put into a tempenature-contrrolled cabinet, turning up the temperature to make the temperature of the center part different from other parts, The pump wave ' s frequency was scanned to make the SBS occur in the sensing fibers under the room Lemperature. The output voltage wave of the system was taken uaing an oscilloscope with the optical pulse as 2 Us.%建立了基于BOTDA(布里渊光时域分析技术)的分布式传感实验系统,该系统由150 mW窄带激光器、50 mw窄带激光器、声光调制器、脉冲发生器、环形器、频率计数器、光电探测器及相应光学器件组成.进行了温度传感试验,获得传感光纤处于25℃、35℃、45℃及55℃时的布里渊频移谱,通过对不同温度下频移谱峰值进行拟舍得出该系统的温度系数.进行了分布式光纤温度传感试验,将传感光纤分成3段,中间段置于温控箱中,调节温控箱的温度,使中间段温度不同于其他两段,扫描泵浦激光频率,使得处于室温下的传感光纤中发生受激布里渊散射,利用示波器获取了当光脉冲为2μs时系统输出电压信号波形.