摘要
实现了一种基于磁流体(MF)磁致折变效应的新型光纤Sagnac磁场传感器。在单模-无芯-单模(S-N-S)结构中,当外界折射率小于且接近无芯光纤(NCF)的折射率时,NCF可以看作阶跃型的多模光纤(MMF)。实验测量了传感器在不同外界磁场强度下的透射光谱,研究了其磁场传感特性。结果表明,由于MF的磁致折变效应,随着垂直于传感器方向的外界磁场强度的增加,环绕NCF的MF折射率减小,从而引起透射谱的干涉峰光强增加。整个实验装置处于室温20℃,在波长1 557.5nm处,磁场传感灵敏度为0.33dB/mT;在波长1 580.1nm处,磁场传感灵敏度为0.32dB/mT。本文传感器灵敏度高、无磁滞现象和消光比稳定。搭建了相应的光电检测系统,将某一波长光强的改变转化为电信号,且测得相对误差小于3%,具有很好的应用前景。
This paper propose a new type sagnac magnetic field fiber sensor based on the magnetorefractive effect of magnetic fluid.In the single mode-no-core- single mode （S-N-S） structure,when the external reflective index is less than but close to that of no-core fiber,the fiber can be seen as a step-index multimode fiber （MMF）.The tran smission spectra of the sensor under different external magnetic fields are mea sured,and is the magnetic field sensing performance studied.The results show that due to the magnetic field can change the direction of ligh t propagation,with the magnetic field strength perpendicular to the sensor direction increasing,the magnetic-fluid-c lad′s reflective index decreases,and the interference peak intensity of the transmission spectrum increases.The w hole experimental device is placed under 20℃,the sensitivi ty of the magnetic field sensing is at 1580.1nm is 0.33dB/m T,and the sensitivity at 1595.1nm is 0.32dB/mT.Compared wit h the previous,the proposed sensor has higher sensitivity,a stable extincion and no hysteresis phenomenon.The corresponding photoel ectric system is built to convert the detection of variation in light intensity into the voltage measurement,the relat ive error is less than 3%,and it has good application prospect.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2017年第12期1290-1295,共6页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(11274278)
浙江省自然科学基金(Y15F050012))资助项目
