基于全保偏光纤的反射式双折射干涉温度传感器

Reflective birefringent interference temperature sensor based on polarization maintaining optical fiber

为了解决透射式光纤温度传感结构不利于测试、灵敏度不高的问题,提出并设计了反射式熊猫型保偏光纤双折射干涉温度传感器。首先通过理论分析并数值仿真研究了熊猫型保偏光纤传感臂长度、转轴角度与温度传感灵敏度之间的关系,并通过在传感臂端面镀金的方式提高反射率。在此基础上,搭建了光纤温度传感测试系统,测试结果表明,在转轴熔接45°、保偏光纤传感臂长度L=80 cm的条件下,50℃~56℃范围内传感器灵敏度可以达到2.741 nm/℃;在保偏光纤传感臂长度为L=7 cm、转轴熔接30°的条件下,65℃~76℃范围内传感器灵敏度为1.400 nm/℃。最后,把设计的温度传感器用于卫星模型温度的测量实验,验证了传感器应用的可行性及有效性。不同波长波谷的漂移量与温度变化呈现良好的线性关系。

In order to solve the problems that transmissive fiber temperature sensing structure is not conductive to testing and has low sensitivity, a reflective birefringent interference temperature sensor based on panda-styled polarization maintaining optical fiber is proposed and designed. Firstly, through theoretical analysis and numerical simulation, the relationship between the sensing arm length of panda-styled polarization maintaining optical fiber, the angle of the rotation axis and the temperature sensing sensitivity is studied. The reflectivity is improved by plating gold on the end surface of the sensor arm. On this basis, an optical fiber temperature sensing test system was built. The experiment results show that the sensor sensitivity can reach 2.741 nm/℃ in the temperature range of 50℃~56℃ under the conditions of the two polarization maintaining fibers fusion spliced with rotating polarization axes by 45° and polarization maintaining fiber sensing arm length of L=80 cm. The sensor sensitivity is as high as 1.400 nm/℃ in the temperature range of 65℃~76℃ when the sensing arm length of polarization maintaining fiber is L=7 cm and the two polarization maintaining fibers fusion spliced with rotating polarization axes by 30°. Finally, the designed temperature sensor was used in the temperature measurement experiment of the satellite model, which verifies the feasibility and effectiveness of the sensor application. The different wavelength dip drifts show good linear relationship with temperature.