Magnetic Field Sensor Based on Backscattered Intensity Using Ferrofluid

A magnetic field sensor based on backscattered intensity of a single mode fiber immersed in a ferrofluid is experimentally demonstrated. An OTDR system is used to interrogate the reflected power at the fiber end face, revealing >2 dB of modulation for magnetic field changes up to 1525 Gauss. The sensor shows the same response when used in remote and multiplexed configurations, demonstrating the high potential and versatility of this sensing approach.