Zhang Fan, Su Baijin, Zhong Lixi, Qi Beibei, Xu Ou, Qin Yuwen
Appl Opt. 2022 Apr 1;61(10):2598-2603. doi: 10.1364/AO.450660.
An all-fiber Mach-Zehnder interferometer (MZI) using ring core few-mode fiber (RC-FMF) for curvature sensing is proposed and experimentally demonstrated. The MZI was fabricated by splicing a segment of RC-FMF between two pieces of single-mode fiber (SMF). With the benefit of a RC of the central axis of the RC-FMF, the sensor is more sensitive to curvature compared to other fiber sensors based on ordinary SMF or FMF. Curvature measurement can be achieved by monitoring the wavelength shift of interference dips. Experimental results have shown that the sensitivity of curvature sensing can reach up to -4.370/, within the range of 1.199-1.549. Also, the temperature sensing characteristics of the sensor are measured, and the maximum temperature sensitivity is 57.6 pm/°C, ranging from 25°C to 45°C. The proposed MZI sensor has excellent potential for curvature measurement of building structural health monitoring, bridge engineering, and more.
提出并通过实验验证了一种采用环形芯少模光纤（RC-FMF）用于曲率传感的全光纤马赫-曾德尔干涉仪（MZI）。该MZI通过在两段单模光纤（SMF）之间熔接一段RC-FMF制成。得益于RC-FMF中心轴的环形结构，与其他基于普通SMF或FMF的光纤传感器相比，该传感器对曲率更敏感。曲率测量可通过监测干涉凹陷的波长偏移来实现。实验结果表明，在1.199-1.549范围内，曲率传感灵敏度可达-4.370/。此外，还测量了该传感器的温度传感特性，在25°C至45°C范围内，最大温度灵敏度为57.6 pm/°C。所提出的MZI传感器在建筑结构健康监测、桥梁工程等曲率测量方面具有优异的潜力。
