In this work, a dual refractive index and temperature sensor based on an interferometric system and on the empirical mode decomposition (EMD) algorithm is presented. Here, it is shown that the EMD provides a comprehensive way to analyze and decompose complex reflection spectra produced by an interferometric filter build at the tip of an optical fiber. By applying the EMD algorithm, the spectrum can be decomposed into a set of intrinsic mode functions (IMF) from which the temperature and the refractive index can be easily extracted. Moreover, the proposed methodology provides a detailed insight of the behavior of this type of interferometric sensors and allows widening of the dynamic measurement ranges of both variables. Here, for proof of principle purposes, a filter based on a stack of three layers (two of them were thermo-sensitive) was fabricated. Finally, it is shown that the proposed methodology can decompose the experimental measured spectra and to determine the refractive index and the temperature, supporting the mathematical model.

中文翻译：

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基于经验模态分解算法的同时测量折射率和温度的光纤FP传感器。

在这项工作中，提出了一种基于干涉系统和经验模态分解（EMD）算法的双折射率和温度传感器。在此显示，EMD提供了一种综合的方法来分析和分解由位于光纤尖端的干涉式滤光片产生的复杂反射光谱。通过应用EMD算法，可以将光谱分解为一组固有模式函数（IMF），从中可以轻松提取温度和折射率。此外，所提出的方法提供了对这种类型的干涉传感器的行为的详细了解，并且允许拓宽两个变量的动态测量范围。在这里，为证明原则，制造了一个基于三层堆叠的过滤器（其中两层是热敏的）。最后，表明所提出的方法可以分解实验测得的光谱并确定折射率和温度，从而支持数学模型。