In this work, a magnetic sensing scheme based on whispering gallery mode (WGM) hollow microbubble resonator (HMR) filled with magnetic fluid (MF) is proposed. The HMR is made by the pressure-assisted arc discharge method on the microcapillary. WGM is excited by evanescent fields in HMR. The quality factor of resonator is 4.02$\times$10⁶. Then, the influence of the wall thickness of HMR and the concentration of MF on the sensor is studied both theoretically and experimentally. When MF is infiltrated in the HMR, the refractive index (RI) of the MF increases with the increase of the magnetic field intensity, resulting in the shift of the resonance wavelength. By reducing the wall thickness, the magnetic sensing sensitivity is increased from 2.6 pm/mT to 25.21 pm/mT within the magnetic field intensity range of 2 mT–20 mT. In addition, the increase in the concentration of MF and the clustering phenomenon caused by it have also been observed. This work provides a novel magnetic sensing scheme, and the proposed WGM resonator has great application prospects in optofluidic sensing.

在这项工作中，提出了一种基于充满磁性流体 (MF) 的回音壁模式 (WGM) 中空微泡谐振器 (HMR) 的磁传感方案。HMR 是通过微毛细管上的压力辅助电弧放电方法制成的。WGM 被 HMR 中的渐逝场激发。谐振器的品质因数为 4.02$\times$10 ⁶ . 然后，从理论上和实验上研究了HMR壁厚和MF浓度对传感器的影响。当MF渗入HMR时，MF的折射率（RI）随着磁场强度的增加而增加，导致共振波长的偏移。通过减小壁厚，在 2 mT–20 mT 的磁场强度范围内，磁感应灵敏度从 2.6 pm/mT 增加到 25.21 pm/mT。此外，还观察到MF浓度的增加及其引起的聚集现象。这项工作提供了一种新颖的磁传感方案，所提出的 WGM 谐振器在光流体传感中具有很大的应用前景。