A coaxial cable magnetic field sensor based on ferrofluid filled Fabry-Perot interferometer structure

A ferrofluid filled coaxial cable Fabry-Perot interferometer is proposed for magnetic field sensing. Both the interferogram shift and the reflection intensity change of the sensor response are studied when external magnetic field is applied. The sensor is tested to work from 0 G to 160 G, and has a highly linear response above 50 G, with the sensitivity of 459 kHz/G. This sensor can be integrated into a coaxial cable sensing platform for multi-function or distributed sensing applications.