High-Sensitivity Refractive Index Sensor Based on a Cascaded Core-Offset and Macrobending Single-Mode Fiber Interferometer
High-Sensitivity Refractive Index Sensor Based on a Cascaded Core-Offset and Macrobending Single-Mode Fiber Interferometer
复制标题
基于级联纤芯偏移和宏弯单模光纤干涉仪的高灵敏度折射率传感器
DOI：
10.3389/fmats.2020.595437
复制
发表时间：
2021-01-27
影响因子：
3.2
通讯作者：
Cheng, Yu
中科院分区：
文献类型：
--
作者：
Teng, Chuanxin;Zhu, Yongjie;Cheng, Yu
提出了一种基于级联纤芯偏移和宏弯光纤结构的高灵敏度马赫-曾德尔干涉仪（MZI），用于折射率（RI）测量。纤芯偏移结构使得纤芯模式耦合到包层模式，并且其中一些模式在宏弯结构处重新耦合回纤芯，形成模型干涉效应。液体折射率可以通过监测模态干涉的光谱位移来测量。通过实验研究了具有不同宏弯半径和核心偏移量的干涉仪的RI传感性能。实验结果表明，当纤芯偏移量为2 μm、宏弯半径为5.5 mm时，RI为1.43时，灵敏度可达699.95 nm/RIU。还测试了所提出的传感器的温度依赖性，获得了 0.112 nm/℃ 的温度灵敏度。
A high-sensitivity Mach-Zehnder interferometer (MZI) based on the cascaded core-offset and macrobending fiber structure is proposed for refractive index (RI) measurement. The core-offset structure makes the fiber core mode couple to the cladding modes, and some of them recouple back to the fiber core at the macrobending structure forming a model interference effect. The liquid RI can be measured by monitoring the spectral shift of the modal interference. The RI sensing performances for the interferometers with different macrobending radii and core offsets are investigated experimentally. Experimental results show that when the core offset is 2 mu m and the macrobending radius is 5.5 mm, the sensitivity can reach 699.95 nm/RIU for the RI of 1.43. The temperature dependence for the proposed sensor is also tested, and a temperature sensitivity of 0.112 nm/degrees C is obtained.