U-bent single-mode-multimode-single-mode fiber optic magnetic field sensor based on magnetic fluid

摘要

A magnetic field sensor based on a U-bent single-mode-multimode-single-mode (SMS) fiber structure and magnetic fluid (MF) is presented and demonstrated experimentally. The U-bent and straight sensors are compared, and the influence of the diameter of the no-core fiber (NCF) on the sensitivity of the U-bent sensor is investigated. The experimental results show that the sensitivity of the sensor can be improved by bending the NCF and decreasing the NCF diameter. The following magnetic field sensitivities have been achieved: 3185.2 pm/mT and 5.6 dB/mT, based on dip wavelength and transmission loss demodulations, respectively.