Magnetic field sensor based on the magnetic-fluid-clad combined with singlemode–multimode–singlemode fiber and large core-offset splicing structure

Abstract

A simple, compact optical fiber magnetic field sensor is proposed and experimentally demonstrated in this paper. It is based on the magnetic-fluid-clad combined with singlemode–multimode–singlemode fiber structure and large core-offset splicing structure. It was protected by a section of capillary tube and was sealed by UV glue. A sensing property study of the combined optical fiber structure and the proposed sensor were carried out. The experimental results show that the sensitivity of the refractive index of the optical fiber sensing structure is up to 156.63 nm/RIU and the magnetic field sensitivity of the proposed sensor is up to −97.24 pm/Oe in the range from 72.4 Oe to 297.8 Oe. The proposed sensor has several other advantages, such as simple structure, small size, easy fabrication and low cost.

SPR based magnetic-field sensing in microchannelled PCF: a numerical approach

“…The resulting magnetic field sensitivity is found to be 564 pm Oe −1 (5.64 nm/mT) for magnetic field strength varying from 90 Oe to 400 Oe and 160 pm Oe −1 for magnetic field varying from 750 Oe to 1000 Oe. This is a substantial improvement from the perspective of sensitivity values of magnetic field sensors reported previously [12][13][14]21]. The decrease in sensitivity at stronger magnetic field strength could be attributed to the slower variation in RI of MF as a function of magnetic field beyond 600 Oe (see figure 7(b)).…”

“…Detection of magnetic field with optimum resolution is extremely important in long-haul electrical networking and military warfare, as well as in scientific and industrial fields. A wide range of fiber based interferometers using conventional fibers, tapered fibers, and photonic crystal fibers have been proposed and demonstrated for the detection of magnetic field [12][13][14][15][16]. However, stability of the interferometer based devices is a concern.…”

Fabrication and Sensing Application of Phase Shifted Bragg Grating Sensors

“…With the increase of magnetic field intensity, the central wavelength of phase shift peak shifts to the long wavelength direction at a linear rate of 2.42 pm/Oe, and the intensity sensitivity is 0.044 dB/Oe. The device based on PS-FBG is shorter and has higher resolution than other types of MF-coated fiber sensors [ 56 , 57 , 58 , 59 ]. It is worth noting that magnetic fluid has magnetic saturation effect, which will limit the measurement range.…”

Singlemode-Multimode-Singlemode Fiber Structures for Sensing Applications—A Review

“…Based on the above SMS fiber structures, there are many reports which involve combinations an SMS fiber structure with other fiber structures to achieve unique properties, such as multiple parameter measurement, sensitivity improvement, etc. air hole in MMF [141], (d) SMSMS [143], (e) SMF sandwiched between air hole and HCF [146], (f) FBG between two NCF [147], (g) MMF-1+MMF-2 [148], (h) SCF+MMF [151], (i) LPG [155], (j) reflective MMF+NCF [160], (k) core-offset FBG [161], (l) SMS+core-offset SMF [163], (m) round shape [170], (n) twist in input SMF [171], (o) MMF+SCF waist-enlarged [172] and (p) both ends waist-enlarged MMF [173]. (Fig.…”

“…8(k)) [161][162], SMS misaligned with output SMF (Fig. 8(l)) [163][164][165][166], S-shaped core-offset connection [167][168] and the use of an air gap between the SMS and SMF [169].…”