Magnetic field sensor utilizing bent fiber taper and magnetic fluid

A magnetic field sensor is demonstrated by placing a bent-fiber taper modal interferometer inside a magnetic fluid sealed with an organic glass base. Owing to the strong refractive index dependency of the interferometer and magneto-optics property of the fluid, our sensor exhibits high sensitivity to the external magnetic field change. A linear wavelength dependency of similar to 58pm/Oe is experimentally obtained within a magnetic field range from 30 to 80 Oe. Our structure is featured of high sensitivity, fiber-compatibility, compactness, and robustness.