双通道抛物线型多模光纤位移传感器输出特性

Properties of the Two-way Optical Fiber Sensor for Displacement Based on ParabolicIndex Fiber

本文根据稳态输入条件下光纤输出光强的远场分布导出了发射光纤折射率为抛物线型分布时，双通道非对称光强反射式位移传感器的输出特性参量Φ与移位ｄ的关系．理论计算和实际测量均表明，输出特性曲线不存在所谓的光峰结构，输出特性参量Φ与位移 ｄ是—一对应的单值关系．这种光纤位移传感器的灵敏度仅决定于传感器的结构参数，与光纤中传输的光强无关．改变传感器的结构参数即可改变传感器的测量范围和灵敏度．

In this paper, the relation between output parameter Φ of the two-way optical fiber sensor and displacement d is derived, according to far field distribution of light thrown by probing fiber with parabolic index of refraction, under steady input condition. The calculation and measurement shows that there is no a optical peak structure in the characteristic curve, and output property parameter Φ is single-valued relationship to the displacement d. Sensitivity of the sensor is not related to intensity of light. The measurement region and sensitivity of the sensor can be changed by selecting different parameter of structure.