Magnetic Field Sensing Characteristics Based on Optical Microfiber Coupler Interferometer and Magnetic Fluid

Abstract

In this paper, a novel and compact magnetic field sensor based on the combination of an optical microfiber coupler interferometer (OMCI) and magnetic fluid (MF) is proposed. The sensor is made up of an OMCI cover with polydimethylsiloxane (PDMS) and MF, and it uses MF as a material for adjusting the magnetic refractive index and magnetic field response. The sensing characteristics of the sensor are analyzed, and the experimental test is carried out. Under the condition of the same OMC waist length, the sensor sensitivity increases with the decrease of the OMC waist radius. The sensitivity of 54.71 and 48.21 pm/Oe was obtained when the OMC waist radius was set at 3.5 and 4 μm, respectively. In addition, we also tested the sensing response time and vector response characteristics of the sensor. At the same time, we discuss the demodulation idea about the cross-sensitivity of the magnetic field and temperature. The sensor has the advantages of high sensitivity, low cost, small size, optimized performance, and convenient integration. It has huge application potential in the fields of navigation and industrial intelligent manufacturing.

Research Progress on Magneto-Refractive Magnetic Field Fiber Sensors

“…Vector magnetic field sensing for TF is also a concern of researchers. Qin et al [ 58 ] exploited an MCF to fabricate a 2D vector magnetic field sensor. Under a magnetic field intensity of 50 Oe, the proposed sensor has a good vector property.…”

Spectral and magnetic field dependence of the birefringence of a magnetic fluid

“…Although magnetic fluid as a system consisting of magnetic nanoparticles of the order of tens of nanometers dispersed in a suitable liquid mediuma carrier liquid, has been known for several decades and many practical applications use the unique mechanical properties of magnetic fluid 1 , its intensive use in optics has only been observed in the last two decades. Today, it is known that the magnetic field affects the refractive index of the magnetic fluid 2 , which allows its use in magnetic field sensors [3][4][5][6] or modulators 7 of signals propagating through an optical fiber. Another optical property, absorption, can be used in medicine for a controlled increase in the ambient temperature near tumor cells 8 or in the field of optical filtering for the construction of optical filters 9 the spectral transmittance of which is tuned by an external magnetic field.…”