All-fiber magnetic-field sensor based on microfiber knot resonator and magnetic fluid

Abstract

All-fiber magnetic-field sensor based on a device consisting of a microfiber knot resonator and magnetic fluid is proposed for the first time in this Letter. Sensor principles and package technology are introduced in detail. Experimental results show that the resonance wavelength of the proposed sensor regularly varies with changes to the applied magnetic field. When the magnetic field is increased to 600Oe, the wavelength shift reaches nearly 100pm. Moreover, the sensor responding to the 50Hz alternating magnetic field is also experimentally investigated, and a minimal detectable magnetic-field strength of 10Oe is successfully achieved.