基于BOTDA的分布式光纤高温传感研究(特邀)

Distributed fiber high-temperature sensing based on BOTDA(invited)

基于布里渊光时域分析(Brillouin optical time-domain analysis,BOTDA)测量技术分别研究了单模光纤、光子晶体光纤和镀金光纤在1100℃、1200℃和1000℃的高温传感特性,通过对石英光纤的布里渊频移(Brillouin frequency shift,BFS)跳跃现象和涂覆层燃烧现象进行研究,指出石英光纤均需要退火才能够达到热稳定状态。退火后,三种光纤的布里渊频移随温度呈非线性变化。其中,单模光纤和光子晶体光纤高温状态下涂覆层气化,二氧化硅发生晶化导致其机械强度大幅下降,因此仅能作为一次性高温传感器;镀金光纤由于金涂层具有较高的熔点和良好的气密性,高温退火后仍然能够保持良好的机械强度,因此可以作为一种重复使用的高温传感器。该研究有望为高温传感应用(如涡轮发动机内部温度监测)提供一种技术参考。

In this paper,the high temperature sensing properties of single-mode fiber,photonic crystal fiber,and gold-coated fiber at 1100℃,1200℃,and 1000℃were studied based on Brillouin optical time-domain analysis(BOTDA).The fact of Brillouin frequency shift(BFS)hopping and the coating burning indicated that the silica fiber should be annealed to reach a thermally stable state.After annealing,the BFS of the three kinds of fibers increased with temperature nonlinearly.The coating of single-mode fiber and photonic crystal fiber burned at high temperatures.And the crystallization of silicon doped its mechanical strength,indicating that it can only be used as a one-time high-temperature sensor.The gold-coated fiber with a higher melting point and better hermeticity can maintain good mechanical strength after high-temperature annealing,so it is a reusable high-temperature sensor.The research in this paper showed the potential for high-temperature sensing applications such as temperature monitoring of turbine engines.