基于保偏光纤模式干涉的温度传感技术

基于Sagnac光纤干涉仪偏振非互易的光纤温度传感器的理论、方案和相关技术,利用光强度直接测量的信号检测技术,实现了单点温度传感并进行了实验验证.实验和测试表明:这种温度传感器达到了0.01℃的温度分辨率和稳定性,通过改变温度传感头的长度和传感保偏光纤的双折射率,可方便地调节其测量范围.同时又提出了一种新的反射型保偏光纤温度传感方案并研制出微小型保偏光纤温度传感头.在此基础上,实现了多点温度测量,研制出大型变压器绕组温度监控用多点温度传感系统,在0～200 ℃的温度范围内达到了0.5℃的测量精度和分辨率,研制的传感头满足高电压绝缘和热油、热蒸汽的恶劣环境要求.

Temperature sensing technology based on mode interference in polarization maintaining fiber

The theory,scheme and related technologies based on the polarization nonreciprocal optical fiber temperature sensor in a Sagnac interferometer were investigated in detail.A point-type temperature sensor prototype was developed and tested in which the sensing signal detection technology was based on light intensity measurement.The experimental results show that the temperature sensor Can reach to the stability and resolution of temperature measurement of 0.01℃.and the measurement range Can be adjusted conveniently by changing the length of the temperature probe and birefringence of the polarization maintaining fiber(PMF)used as sensing element.In addition,a reflection-type PMF temperature sensing scheme was also proposed,and a mini PMF temperature probe Was fabricated.Finally,in order to measure the temperature of power transformer winding,a multi-point temperature sensing system was developed,and the system reached the measurement precision of 0.5 ℃ in the range of 0-200 ℃ and the sensor probes can satisfy the harsh environmental demand of high voltage insulation,hot oil andhot vapor.