DOI:10.16136/j.joel.2023.02.0294基于并联法布里-珀罗干涉仪游标效应的增敏光纤湿度传感器马行超,张熙梓,郭允,吴玉纯,王东宁,徐贲*(中国计量大学光学与电子科技学院,浙江杭州310018)摘要:为了提高光纤湿度传感器的灵敏度,提出了一种基于并联光纤法布里-珀罗干涉仪(Fabry-Perotinterferometers,FPIs)游标效应的增敏型湿度传感器,并进行了实验验证。该传感器由两个基于内径4μm石英毛细管的光纤FPI通过2×2耦合器并联组成,其中一个FPI作为传感FPI,其末端镀有湿敏特性的琼脂糖薄膜,另一个作为参考FPI。论文分析了器件的湿度传感工作原理,实验结果论证了该理论分析的正确性。实验显示,并联FPI游标效应器件在40%RH—60%RH范围内其灵敏度高达0.8439nm/%RH,较之单一FPI的灵敏度提高了9倍,是并联FPI反射谱直接波谷追踪波长解调灵敏度的44倍。增加FPI末端湿敏膜厚度,其灵敏度进一步提高至1.12nm/%RH。该传感器制备简单、尺寸小、灵敏度高,在湿度测试方面具有潜在的应用价值。关键词:光纤传感;法布里-珀罗干涉仪(FPI);游标效应;湿度中图分类号:TN253文献标识码:A文章编号:1005-0086(2023)02-0113-07Sensitivity-enhancedfiberhumiditysensorbasedonparallelFabry-PerotinterferometerswithVerniereffectMAXingchao,ZHANGXizi,GUOYun,WUYuchun,WANGDongning,XUBen*(CollegeofOpticalandElectronicTechnology,ChinaJiliangUniversity,Hangzhou,Zhejiang310018,China)Abstract:Toattainhighhumiditysensitivity,asensitivity-enhancedsensorbasedonparallelfiberFabry-Perotinterferometers(FPIs)withtheVerniereffectisproposedandexperimentallydemonstrated.ItismadeupoftwoopticalfiberFPIs,eachofwhichisbasedonashortcapillarysectionwithaninnerdiam-eterof4μm.A2×2couplerconnectsthetwoFPIsinparallel.ThesensingelementisoneFPIcoveredwithhumidity-sensitiveagarosefilmatitsendface,whereasthereferenceelementistheother.Thethe-oreticalstudyofthesensor'soperatingprincipleandtheexperimentalfindingsareingoodagreement.Withintherangeof40%RH—60%RH,highsensitivityof0.8439nm/%RHisachieved.Itis44timesmoresensitivethanthedirecttracingofaspecificresonancedipinthesuperimposedreflectionspectrumandis9timesmoresensitivethanasingleFPI.Thethicknessofthehumidity-sensitivefilmisthenincreased,significantlyimprovingthehumidity...
