Abstract A novel fiber bending sensor is proposed based on a home-made seven-core fiber (SCF). The sensing head is formed by splicing a piece of a SCF between two sections of single-mode fibers(SMFs). Two super modes with most of mode energy in the central fiber core and in the six outsider fiber cores are exited in the SCF, which ensures the Mach–Zehnder interferometer (MZI) structure of the proposed sensor and form the mode interference spectrum in the lead-out SMF. The relationship between the dip wavelength shift of the interference spectrum and the bending curvature of the SCF is experimentally investigated. The temperature response of the SCF bending sensor is also experimentally investigated Our experimental results show that the MZI sensor exhibits a high bending sensitivity of 2.65 nm/m−1 and a temperature sensitivity of 0.021 nm/°C, respectively. The compact size, low cost and high sensitivity makes the MZI sensor a good candidate for bending sensing application.

中文翻译：

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基于七芯光纤的高灵敏度弯曲传感器

摘要 提出了一种基于自制七芯光纤（SCF）的新型光纤弯曲传感器。传感头是通过在两段单模光纤 (SMF) 之间拼接一块 SCF 形成的。在中心纤芯和六个外部纤芯中具有大部分模式能量的两个超级模式在 SCF 中退出，这确保了所提出的传感器的马赫-曾德干涉仪 (MZI) 结构并在引线中形成模式干涉光谱- 输出 SMF。通过实验研究了干涉光谱的倾角偏移与 SCF 的弯曲曲率之间的关系。还通过实验研究了 SCF 弯曲传感器的温度响应我们的实验结果表明，MZI 传感器具有 2.65 nm/m-1 的高弯曲灵敏度和 0.021 nm/°C 的温度灵敏度，分别。紧凑的尺寸、低成本和高灵敏度使 MZI 传感器成为弯曲传感应用的理想选择。