In this letter, we demonstrate a low-cost fiber loop ring-down (FLRD) magnetic field sensor using frequency-shifted interferometry.  A D-shaped fiber coated with magnetic fluid was used as the sensor head for enhancing the sensitivity and improving the stability. With this scheme, the magnetic field was sensed in the space domain by measuring the ring-down distance, and its measurement accuracy was improved by introducing a temperature controller. The experimental results showed that a sensitivity of 2.53 × 10−3 (km−1ċG−1) was achieved, and a stability of 0.146% was obtained, which is better than those of the current time-domain FLRD sensors based on evanescent field effect.

中文翻译：

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使用频移干涉测量法和涂有磁流体的 D 形光纤的光纤环衰荡磁场传感器


在这封信中，我们展示了一种使用频移干涉测量法的低成本光纤环路衰荡（FLRD）磁场传感器。采用涂有磁流体的D形光纤作为传感头，以增强灵敏度并提高稳定性。该方案通过测量衰荡距离在空间域感知磁场，并通过引入温度控制器提高了测量精度。实验结果表明，灵敏度达到2.53×10−3（km−1ċG−1），稳定性为0.146%，优于目前基于倏逝场效应的时域FLRD传感器。