Abstract A simple, high-sensitivity strain sensor based on a sealed optical microfiber coupler (OMC) was proposed and demonstrated. Affected by the strain, the effective refractive index (RI), microfiber length, microfiber diameter changes the coupling coefficient of the OMC. Due to the uneven force of the port3 and port4, the strain sensitivity after encapsulation will improve, which is proved in the experiment. The mechanical simulation demonstrates that there is a dependence between strain sensitivity and waist diameter. The sensor with a 2.3 μm waist diameter presents a sensitivity of −18.351 pm/μe regarding the variation of axial strain from 10 to 1200μe, which was one order of magnitude higher than that of optical strain sensors based on fiber Bragg gratings. Experimental results demonstrate that the OMC sensor exhibits high sensitivity, strong stability and the capability of simultaneous measurement of strain and temperature.

中文翻译：

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基于密封光学微纤维耦合器的高灵敏度应变传感器

摘要 提出并演示了一种基于密封式微光纤耦合器 (OMC) 的简单、高灵敏度应变传感器。受应变的影响，有效折射率（RI）、微纤长度、微纤直径改变了 OMC 的耦合系数。由于port3和port4受力不均，封装后的应变敏感性会有所提高，这在实验中得到了证明。机械模拟表明应变敏感性和腰部直径之间存在相关性。腰部直径为 2.3 μm 的传感器对于 10 到 1200 μe 的轴向应变变化的灵敏度为 -18.351 pm/μe，比基于光纤布拉格光栅的光学应变传感器高一个数量级。实验结果表明，OMC 传感器表现出高灵敏度，