In this article, we report on a carbon-coated optical fiber that is suitable to be used simultaneously as a transmission medium and as a sensor. It consists of a standard single mode fiber (SMF) sleeved in two layers of coating, which provide protection and isolation from external elements. The inner layer is made of carbon, whereas the outer is made of polymer. When the fiber is subjected to mechanical stress, the electrical resistance of the carbon layer changes accordingly. The voltage variations caused by the former can be measured with high accuracy and without interfering with the light propagating through the SMF. In this work, the feasibility of this operating principle is demonstrated in a low coherence Michelson interferometer in which electrical and optical signals were measured simultaneously and compared to each other. Results indicate that electrical measurements are as precise as the optical ones and with linear behavior, reaching a sensitivity of 1.582 mV/με and able to detect vibrations down to 100 mHz.

中文翻译：

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用于光电应变和振动传感的碳涂层光纤

在本文中，我们报告了一种适合同时用作传输介质和传感器的碳涂层光纤。它由套有两层涂层的标准单模光纤 (SMF) 组成，可提供保护并与外部元件隔离。内层由碳制成，而外层由聚合物制成。当纤维受到机械应力时，碳层的电阻随之变化。由前者引起的电压变化可以高精度测量，并且不会干扰通过 SMF 传播的光。在这项工作中，这种工作原理的可行性在低相干迈克尔逊干涉仪中得到了证明，其中电信号和光信号被同时测量并相互比较。结果表明，电气测量与光学测量一样精确，并且具有线性特性，灵敏度达到 1.582 mV/με，并且能够检测低至 100 mHz 的振动。