Magnetic Field Sensing Based on Multimode Fiber Specklegrams

We demonstrate a fiber magnetic field sensor based on multimode fiber specklegrams. The magnetic field is detected by measuring the change of speckle patterns with digital correlation technology. When the magnetic induction increases by 50 mT, the response of correlation coefficient is more than 0.35. The sensitivity of the sensor is 0.00705 mT(-1) for the magnetic field range of 50100 mT, and the resolution is 0.284 mT. The temperature cross sensitivity is studied by establishing the sensing matrix. In addition, dynamic range expansion and magnetic field direction sensing are explored as the application extensions of this kind of sensor.

Automated summary

The fiber magnetic field sensor demonstrated in this study is based on multimode fiber specklegrams and utilizes digital correlation technology to detect changes in speckle patterns. It shows a high sensitivity of 0.00705 mT(-1) and a resolution of 0.284 mT for a magnetic field range of 50100 mT. Temperature cross sensitivity is studied, and potential applications such as dynamic range expansion and magnetic field direction sensing are explored as extensions for this type of sensor.