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 ⁻¹ ċG ⁻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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使用频移干涉法和D形光纤涂覆磁性流体的光纤环路振铃向下磁场传感器

在这封信中，我们演示了一种使用频移干涉法的低成本光纤环路衰荡（FLRD）磁场传感器。使用涂有磁性流体的D形光纤作为传感器头，以提高灵敏度和稳定性。利用该方案，通过测量振铃距离来在空间域中感测磁场，并且通过引入温度控制器来提高其测量精度。实验结果表明，灵敏度2.53×10 ^-3（千米 ^-1 CG ^-1 ）达到了，并获得了0.146％稳定性，这比基于渐逝场与当前时域FLRD传感器的更好影响。