基于光纤锥和多模渐变光纤的马赫-曾德尔干涉仪的传感特性研究  

A fiber Mach-Zehnder interferometer based on waist-enlarged fiber taper and graded-index multimode fiber

作　　者：张芸山 乔学光[1,2] 邵敏[1] 李辉栋[1] 傅海威[1] 荣强周[2] 赵娜[1] 

机构地区：[1]西安石油大学光电油气测井与检测教育部重点实验室,陕西西安710065 [2]西北大学物理系,陕西西安710069

出　　处：《光电子．激光》2014年第9期1662-1667,共6页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61327012、61275088、61077060);教育部科技创新项目(Z08119);陕西省教育厅重点实验室科研计划(12JS077)资助项目

摘　　要：提出了一种基于光纤锥和纤芯失配光纤结构的马赫-曾德尔干涉（MZI）传感器。在距离单模光纤（SMF）锥25mm处熔接一段长30mm的多模渐变光纤（GI MMF）,形成SMF-光纤锥-SMFGI MMF-SMF结构。其中,光纤锥起到增加包层模能量的作用,GI MMF为传感臂。传感器外界环境温度、折射率及应力的改变都会使传感器的纤芯基模和包层模的光程差发生改变,从而引起传感器干涉谱发生变化,通过监测干涉谱的变化可以实现对外界物理量的测量。实验研究结果表明,当环境溶液温度在30~89℃范围内变化时,传感器的温度灵敏度为78.6pm/℃,线性度为0.997;环境溶液折射率在1.333~1.394变化范围内,传感器的折射率灵敏度为81.48dB/RIU,线性度为0.989;轴向应变在0~933.3με变化范围内,传感器的应变灵敏度为0.33×10-2 dB/με,线性度为0.998。本文传感器可以实现多个物理量的同时区分测量。An in-fiber Mach-Zehnder interferometer （MZI） based on waist-enlarged fiber taper and graded-indexmultimode fiber is proposed and demonstrated in this paper. The sensor head is fabricated by fusion splicing a 30 mm graded-index multimode fiber with a fiber taper, and the distance between them is 25 mm,thus forming SMF-taper-SMF-GI MMF-SMF fiber structure. The optical fiber taper can increase cladding mode energy,gradient multimode optical fiber serves as sensing arm,and the changes of the ambient temperature, refractive index and the axial stress will make the sensor core mode and cladcling mode of optical path difference varied, causing interference sensor spectral change. Monitoring the spectra variation can determine the ambient physical parameters. The experimental results show that the temperature sensitivity of the sensor is 78. 6 pm/℃ with a linearity of 0. 997 in the water temperature range of 30-89℃ the refractive index sensitivity is 81.48 dB/RIU with a linearity of 0. 989 in the refractive index range of 1. 333-1. 394 RIU;the strain sensitivity is 0.33X 10-2 dB/με with a linearity of 0. 998 in the strain range of 0--933.3με. The sensor has advantages of simple fabrication,low cost,sim- ultaneous measurement of multiple physical parameters.

关 键 词：光纤锥 多模渐变光纤(GI MMF) 马赫-曾德尔干涉仪(MZI) 

分 类 号：TN253[电子电信—物理电子学]