Research on optical fiber magnetic field sensors based on multi-mode fiber and spherical structure

• Published in: Optoelectronics letters Vol. 13; no. 1; pp. 16 - 20
• Main Author: 王艳 童峥嵘 张卫华 栾盼盼 赵月 薛力芳
• Format: Journal Article
• Language: English
• Published: Tianjin Tianjin University of Technology 2017; Springer Nature B.V
• Subjects: Interference; Interferometers; Intermodal; Lasers; Magnetic fields; Magnetic fluids; Magnetism; Optical Devices; Optical fibers; Optics; Photonics; Physics; Physics and Astronomy; Segments; Transmission loss
• ISSN: 1673-1905; 1993-5013
• DOI: 10.1007/s11801-017-6195-6

A magnetic field sensor with a magnetic fluid（MF）-coated intermodal interferometer is proposed and experimentally demonstrated. The interferometer is formed by sandwiching a segment of single mode fiber（SMF） between a segment of multi-mode fiber（MMF） and a spherical structure. It can be considered as a cascade of the traditional SMF-MMF-SMF structure and MMF-SMF-sphere structure. The transmission spectral characteristics change with the variation of applied magnetic field. The experimental results exhibit that the magnetic field sensitivities for wavelength and transmission loss are 0.047 nm/m T and 0.215 d B/m T for the interference dip around 1 535.36 nm. For the interference dip around 1548.41 nm,the sensitivities are 0.077 nm/m T and 0.243 d B/m T. Simultaneous measurement can be realized according to the different spectral responses.