长距离布里渊光时域反射光纤传感技术进展

大型桥梁坍塌、建筑物倾斜、冰灾造成输电杆塔倒塌大范围停电等自然灾害新闻屡见不鲜,对类似这些设施的监测研究成为热点.布里渊光时域反射(BOTDR)光纤传感具有分布式温度/应变同时传感、单端注入与测量等优点而被人们广泛采用.本文针对长距离光纤传感应用场景,分析了BOTDR传感机理;综述了近20年以来10 km及以上长距离B...

Advances of technologies in long-range Brillouin optical time-domain reflective optical fiber sensing

In recent years,the health monitoring of large bridges,buildings and transmission towers has become a research hotspot.Brillouin optical time-domain reflection(BOTDR)fiber sensing is widely used because of its advantages of distributed temperature/strain simultaneous sensing,single-ended injection and measurement.In this paper,we review the mechanism of BOTDR sensing for long-range fiber sensing applications;the development and key technologies and specific indicator values of 10 km and above long-distance BOTDR fiber sensing system in recent 20 years;we summaries the principle of long-range BOTDR optical fiber sensing system based on technologies of data processing,pulse coding,multi-wavelength detection,high extinction ratio modulation,Raman,narrow linewidth light source and single-photon detection.Further improve the system signal-to-noise ratio,spatial resolution,sensing distance,shorten the measurement time of the whole system,optimize multiple performance parameters;and further increase the sensing parameters excepting temperature/strain,enhance the system function;as well as further addressing temperature/strain cross-sensitivity issues;all will become the future development direction of long-distance BOTDR optical fiber sensing system.