马赫-曾德尔干涉集成化的全光纤磁场与温度传感器

为了简化光纤磁场与温度传感器的结构并提高传感器灵敏度,设计并制作了马赫-曾德尔干涉集成化的全光纤磁场与温度传感器。将单根光纤的马赫-曾德尔模间干涉结构和双臂马赫-曾德尔干涉结构结合:将总长度为1.2m的单模光纤部分制备成长度为2.7cm、锥腰直径为30.1μm的锥形微纳光纤,并得到了拉锥时间与锥腰直径的关系。将锥形微纳光纤放置尼龙槽内并包覆磁凝胶构成传感头,实现模间干涉的马赫-曾德尔磁场传感器;将磁场传感器通过两耦合比为50%∶50%的耦合器并联带有可调谐光衰减器的单模光纤形成马赫-曾德尔干涉的温度传感器。从理论上分析了光谱漂移对磁场和温度传感的特性关系,实验测得室温下磁场强度在25~50mT时,磁场传感的灵敏度为0.301 14nm/mT;在磁场强度为0,温度由25℃升高到30℃时,温度传感的灵敏度为0.518 86nm/℃。该传感器可广泛应用于电力系统放电检测、材料加工、安全监控等领域。

Mach-Zehneder interference all-fiber sensor for measurement of magnetic field and temperature

A Mach-Zehnder interferometer all-fiber sensor for magnetic field and temperature measurement was proposed and experimentally demonstrated for a simplified sensor with improved sensitivity. It combined a Mach-Zehnder modal interferometer and two arms Mach-Zehnder interferometer. A single mode fiber of 1.2 m in length was partly processed into a taper-structured microfiber of 2.7 cm length and a 30.1 μm diameter taper waist. The relationship between the tapering time and the taper waist was investigated. The tapered fiber was placed into a nylon slot and was coated using magnetic sol-gel to fabricate the sensor head. The Mach-Zehnder modal interferometer magnetic field sensor was then complete. The other single mode fiber with a tunable optical attenuator was employed to form the Mach-Zehnder interferometer temperature sensor via two couplers with coupling ratio 50:50. The characteristic relationship between the spectra drift, and the magnetic field/temperature sensing was analyzed theoretically. Experiment results show that the sensitivity of the magnetic field sensor is 0.301 14 nm/mT when the magnetic field intensity ranged from 25 mT to 50 mT at room temperature. The temperature sensor had a sensitivity of 0.518 86 nm/℃ in the range of 25℃ to 30℃ without an applied magnetic field. This sensor has potential applications in numerous areas, including discharge detection systems, material processing, and safety monitoring, etc.