Current or magnetic field sensing is usually achieved by exploiting the Faraday effect of an optical material combined with an interferometric probe that provides the sensitivity. Being interferometric in nature, such sensors are typically sensitive to several other environmental parameters such as vibrations and mechanical disturbances, which, however, inevitably impose the inaccuracy and instability of the detection. Here we demonstrate a polarimetric fiber optic current sensor based on orbital angular momentum modes of an air-core optical fiber. In the fiber, spin–orbit interactions imply that the circular birefringence, which is sensitive to applied currents or resultant magnetic fields, is naturally resilient to mechanical vibrations. The sensor, which effectively measures polarization rotation at the output of a fiber in a magnetic field, exhibits high linearity in the measured signal versus the applied current that induces the magnetic field, with a sensitivity of 0.00128 rad/A and a noise limit of 1×10−5/√Hz$1 \times {10^{ - 5}}/\sqrt {Hz}$. The measured polarization varies within only ±0.1% under mechanical vibrations with the frequency of up to 800 Hz, validating the robust environmental performance of the sensor.

中文翻译：

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基于空芯光纤轨道角动量模式的振动不敏感偏振光纤电流传感器

电流或磁场传感通常是通过利用光学材料的法拉第效应与提供灵敏度的干涉探针相结合来实现的。由于本质上是干涉测量，此类传感器通常对其他几个环境参数（例如振动和机械扰动）敏感，然而，这不可避免地会导致检测的不准确性和不稳定。在这里，我们展示了一种基于空芯光纤轨道角动量模式的偏振光纤电流传感器。在光纤中，自旋轨道相互作用意味着圆形双折射对施加的电流或合成磁场敏感，对机械振动自然具有弹性。该传感器可有效测量磁场中光纤输出端的偏振旋转，在测量信号与感应磁场的施加电流之间表现出高线性度，灵敏度为 0.00128 rad/A，噪声限值为1 × 10 − 5 / √赫兹​$1 \times {10^{ - 5}}/\sqrt {Hz}$。在频率高达 800 Hz 的机械振动下，测量的偏振变化仅在 ±0.1% 范围内，验证了传感器的稳健环境性能。