We demonstrate a compact extrinsic Fabry–Perot interferometer-based fiber-optic sensor that uses magnetostrictive amorphous metallic wire Unitika AF-10 (Fe<sub>77.5</sub>B<sub>15</sub>Si<sub>7.5</sub>) as a sensor gauge for measuring dc magnetic fields. We present a theoretical model based on a Gaussian electric field distribution to analyze the sensor operation as a function of longitudinal air-gap separation. The model shows good agreement with the experimental results. A resolution of 50 nT over a range of 50–40,000 nT with a simple passive temperature-compensation method is obtained.
© 2004 Optical Society of America
Ki D. Oh, Anbo Wang, and Richard O. Claus, "Fiber-optic extrinsic Fabry-Perot dc magnetic field sensor," Opt. Lett. 29, 2115-2117 (2004)