We report on the distributed shape measurement of small deformations produced along the length of an optical fiber. The fiber contains multiple waveguiding cores, each inscribed with weak continuous Bragg gratings. The distributed Bragg-reflectivity data for the fiber cores, obtained from the optical backscatter reflectometry, are used to estimate the local curvature and the position of the fiber. We successfully demonstrate the sensing of periodic microdeformations—approximately 1 µm or less in amplitude and a few hundred µm in length. Such microbends are known to cause attenuation in optical fibers, and the approach presented here can enable a detailed measurement of these microbends in applications ranging from telecommunications cable design to biotechnology, robotics, manufacturing, aerospace, and security.

中文翻译：

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测量光纤中微弯的形状。

我们报告了沿光纤长度产生的小变形的分布形状测量。光纤包含多个波导纤芯，每个纤芯均刻有弱连续布拉格光栅。从光学反向散射反射仪获得的纤维芯的分布式布拉格反射率数据可用于估计纤维的局部曲率和位置。我们成功地演示了对周期性微变形的感知-振幅大约为1 µm或更小，长度大约为数百µm。已知此类微弯会导致光纤衰减，并且此处介绍的方法可以实现这些微弯的详细测量，其应用范围从电信电缆设计到生物技术，机器人技术，制造，航空航天和安全性。