根据薄膜型光纤温度传感器的感温原理及光学薄膜的应力特性, 利用膜层干涉的特征矩阵分析了传感元件的传感特性, 建立了薄膜型光纤温度传感器的热应力特性及其对传感特性影响的理论模型。通过对薄膜和光纤的热光效应和热膨胀特性的分析, 对比了蓝宝石光纤、纯硅芯光纤和普通多模光纤三种光纤基底的热应力-温度特性, 设计了高温传感器传感探头的薄膜膜系, 分析了膜系中每层膜的热应力-温度特性, 以及临界载荷应力特性, 确定所选光纤基底脱膜的临界应力值。通过模拟不同应力作用下的光谱传感特性, 为传感器薄膜敏感探头的稳定性和可靠性提供理论依据和支持, 提高传感器研制的效率。

According to the temperature sensing principle of the fiber optic temperature sensor and the stress characteristics of coating, the theoretical model of the thermal stress characteristics and its influence for sensing characteristics was established by using the characteristic matrix of thin film. The thermal stress-temperature characteristics of the three kinds of fiber, inculding sapphire fiber, pure silicon core fiber and multimode fiber, were compared by analyzing the thermo-optic effect and thermal expansion characteristics of the film and fiber. A thin film formula for high temperature sensing probe was designed. And the thermal stress-temperature characteristics of each film layer of the formula, as well as the critical load stress characteristics, were analyzed, thus the critical load stress value of the selected fiber can be determined. By simulating the spectral sensing characteristics under different stresses, it provides theoretical basis and support for the stability and reliability of sensor-sensitive probes, and improves the efficiency of sensor development.