基于保偏光纤马赫曾德干涉结合布拉格光纤光栅的折射率传感器(英文)

Refractive Index sensor Based on Polarization-Maintaining Fiber M-Z Interferometer with an FBG

为了能同时测量折射率和温度,提出了一种基于保偏光纤马赫曾德干涉仪结合布拉格光纤光栅的折射率传感器。保偏光纤在两个单模光纤之间通过错位熔接形成马赫曾德干涉仪,布拉格光纤光栅连接在马赫曾德干涉仪的输出端用作温度补偿。实验结果表明保偏光纤快轴和慢轴两个正交模式的干涉谱随着折射率的变化而变化,当折射率范围在1.3426到1.3692时,快轴和慢轴方向上的灵敏度分别为-118.38 nm/RIU和-80.02 nm/RIU。当折射率在1.3692到1.4191时,快轴和慢轴方向上的灵敏度分别为48.3 nm/RIU和25.75 nm/RIU。同时通过测量布拉格光纤光栅谐振波长的偏移量,折射率和温度能被同时测量。

In order to measure the refractive index（RI）and temperature simultaneously,a refractive index（RI）sensorbased on a Mach-Zehnder interferometer（MZI）with a fiber Bragg grating（FBG）is proposed. The MZI is fabricated bycore-offset fusion splicing one section of the polarization-maintaining fiber（PMF）between two single mode fibers（SMFs）. A FBG was connected to the output port of the MZI. Part of the MZI interference light was reflected by theFBG. Two independent interference patterns corresponding to fast axis and slow axis modes in the PMF were obtained,and the interference pattern changed with the variation of the RI for the two orthogonal polarization modes. In the RIrange of 1.3426 to 1.3692,the sensitivities of-118.38 nm/RIU and-80.02 nm/RIU for fast axis polarization mode andslow axis polarization mode were obtained,respectively. In the RI range of 1.3692 to 1.4191,the sensitivities of 48.3nm/RIU and 25.75 nm/RIU for fast axis polarization mode and slow axis polarization mode were obtained,respectively.The FBG was used as the temperature compensation and the RI and temperature can be measured simultaneously.