M型少模光纤中模间受激布里渊散射特性及其温度和应变传感特性  

Inter-mode stimulated Brillouin scattering and simultaneous temperature and strain sensing in M-shaped few-mode fiber

作　　者：李雪健 曹敏 汤敏 芈月安 陶洪[1] 古皓 任文华[1] 简伟[1] 任国斌[1] Li Xue-Jian;Cao Min;Tang Min;Mi Yue-An;Tao Hong;Gu Hao;Ren Wen-Hua;Jian Wei;Ren Guo-Bin(Key Laboratory of All Optical Network and Advanced Telecommunication Network,Ministry of Education,Institute of Lightwave Technology,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学光波技术研究所,全光网络与现代通信网教育部重点实验室,北京100044

出　　处：《物理学报》2020年第11期116-124,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61875008,61275092)资助的课题.

摘　　要：少模光纤的受激布里渊散射对于分布式温度/应变传感具有重要应用价值.本文提出一种纤芯折射率呈M型分布的少模光纤,详细研究了光学模式LP01和LP11模式内及模式间的布里渊增益谱.研究结果表明:LP01-LP11模式对的布里渊增益谱中,其相邻两个布里渊散射峰的频率间隔较宽、增益峰值较大且峰值相差较小.通过优化光纤结构参数,提高了基于LP01-LP11模式对布里渊增益谱的温度和应变传感性能,最小误差分别为0.23℃和5.67μe.该研究对探究少模光纤中模式内及模式间的受激布里渊散射特性具有一定的指导意义,对提升同时温度和应变传感测量的性能具有一定参考价值.Stimulated Brillouin scattering(SBS)in a few-mode fiber(FMF)is of significance for the distributed temperature and strain sensing.An FMF with M-shaped refractive index distribution(M-FMF)is proposed in order to improve the performance of simultaneous temperature and strain sensing based on SBS.Propagation of four optical modes is supported by the M-FMF,so that the Brillouin gain spectrum(BGS)can be obtained by both intra-mode and inter-mode SBS.The BGSs produced by the interactions of LP01-LP01 mode pair,LP01-LP11 mode pair,and LP11-LP11 mode pair are analyzed,respectively.Meanwhile,the temperature and strain sensing performance based on the BGS of LP01-LP11 mode pair are studied in detail.Considering a common step-index FMF,only one obvious scattering peak is usually present in the BGS obtained from the interaction between different optical mode pairs,therefore,it is inconvenient to achieve multi-parameter sensing measurement.In this paper,the BGS of LP01-LP11 mode pair has two scattering peaks,which are contributed by the acousto-optic coupling between the acoustic modes L1n(n=1,2)and the optical modes LP01 and LP11.The two Brillouin scattering peaks have large gain values of 0.1004 m–1·W–1 and 0.0463 m–1·W–1,respectively.More importantly,the gain difference between two Brillouin scattering peaks is small,and the frequency interval is 75 MHz,which can be applied to simultaneous temperature and strain sensing.The influences of the refractive index and the fiber core radius on the BGS of LP01-LP11 mode pair are studied.By selecting the optimal structure parameters,we discuss the effect of temperature and strain on the BGS of LP01-LP11 mode pair.The errors for simultaneous temperature and strain measurement are reduced to 0.23℃and 5.67μe.Compared with other reported results,our obtained temperature and strain sensitivity are high and sensing errors are low in the considered M-FMF.In other words,based on the BGS of LP01-LP11 mode pair,the performance of temperature and strain sensing are improved in th

关 键 词：M型少模光纤 受激布里渊散射 布里渊增益谱 传感 温度和应变 

分 类 号：TN253[电子电信—物理电子学] TP212[自动化与计算机技术—检测技术与自动化装置]