基于拉锥单模-多模-单模光纤结构的高灵敏折射率传感器  

High Sensitivity Refractive Index Sensor based on a Tapered Single-mode-Multimode-Single-mode Fiber Structure

作　　者：张英[1] 邹卫文[1] 李新碗[1] 毛经纬[1] 李曙光[1] 姜文宁[1] 陈建平[1] 

机构地区：[1]上海交通大学区域光纤通信网与新型光通信系统国家重点实验室

出　　处：《电子技术（上海）》2012年第1期73-75,共3页Electronic Technology

基　　金：国家973计划(ID2011CB301700)资助;国家自然科学基金项目(60877012;61071011;61001074;61007039;61007052)资助;上海市重大基础项目(10DJ1400402)资助;上海市重点基础项目(09JC1408100)资助

摘　　要：文章介绍基于拉锥单模-多模-单模(SMS)光纤结构的模间干涉仪,当拉伸长度为35mm时形成自由光谱区(FSR)为1.3nm的干涉透射谱,消光比达到10dB。此时拉锥多模光纤的腰椎平坦区直径约为3.85μm,具有较强的倏逝场,可用作高灵敏折射率传感器。实验证明,此拉锥SMS结构在折射率范围1.35-1.36内的灵敏度高达771nm/RIU,能精密监测溶液溶质扩散现象。A modal interferometer is demonstrated by tapering a single-mode- multimode-single-mode （SMS） fiber structure heated by hydrogen flame. An interference fringe with the free spectral range （FSR） of 1.3 nm and extinction ratio of - 10dB is experimentally observed when the tapering length is 35mm. There exists stronger evanescent field in the SMS fiber structure when the waist diameter of the tapered multimode fiber is as thin as -3.85 μ m. The refractive index sensitivity is up to 771nm/RIU in the RI range of 1.35 1.36. The sensor can accurately monitor the diffusion phenomenon of liquid solute.

关 键 词：光纤拉锥 模间干涉 倏逝场 传感 

分 类 号：TN818[电子电信—信息与通信工程]