Low-Coherence Interferometric Fiber Optic Sensor for Humidity Monitoring Based on Nafion® Thin Film †
Low-Coherence Interferometric Fiber Optic Sensor for Humidity Monitoring Based on Nafion® Thin Film †
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DOI：
10.3390/s19030629
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
E. Maciak
中科院分区：
文献类型：
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作者：
E. Maciak
本论文的主要目的是设计和开发简单的光纤法布里-珀罗干涉仪（FPI）相对湿度（RH）传感器器件，重点是高灵敏度和良好的稳定性。RH光纤FPI传感器通过在切割的标准多模（MM）光纤的末端涂覆亲水性Nafion®传感膜来制造。薄膜充当低相干干涉传感结构的有源谐振腔。干涉光束在Nafion®薄膜中产生的条纹图案将随着RH的变化而偏移，因为水分子会使Nafion®薄膜膨胀，从而改变传感结构的光程长度。在这项工作中讨论了基于Nafion®中水蒸气的吸附和解吸的FPI传感器的工作原理以及这种传感器类型的局限性。光纤湿度计在可见光（400-900 nm）光谱区域内进行测试，用于测量室温（RT）下空气中5.5-80%范围内的相对湿度（RH）。光纤湿度传感器具有与商用传感器一样好的响应时间（t90 = 5-80 s）和快速再生时间（t10 = 5-12 s）。
The main aim of this work was the design and development simple fiber optic Fabry-Perot interferometer (FPI) sensor devices for relative humidity (RH) sensing with emphasis on high sensitivity and good stability. The RH fiber FPI sensor is fabricated by coating the end of a cleaved standard multi-mode (MM) fiber with hydrophilic Nafion® sensing film. The Nafion® thin film acts as an active resonance cavity of the low-coherence interferometric sensing structure. The fringe pattern, which is caused by interfering light beam in the Nafion® thin film will shift as the RH changes because the water molecules will swell the Nafion® film and thus change optical pathlength of the sensing structure. The operating principle of a FPI sensor based on the adsorption and desorption of water vapour in the Nafion® and the limitations of this sensor type are discussed in this work. The fiber optic hygrometer was tested in the visible (400–900 nm) region of spectra for measurement of relative humidity (RH) in the range of 5.5–80% at room temperature (RT) in air. The fiber optic humidity sensor has a very short response time (t90 = 5–80 s) and a fast regeneration time (t10 = 5–12 s) as good as commercial sensors.