Intensity-interrogated magnetic sensor based on S-tapered and multimode fiber integrated with ferrofluids

Abstract

In this study, a high-sensitivity intensity-interrogated fiber sensor integrated with ferrofluids is proposed for the measurement of a weak magnetic field (MF) with resolved temperature cross-sensitivity. The MF sensor is fabricated simply by an offset tapering single-mode fiber concatenated with a multimode fiber (MMF), which is then encapsulated into a capillary tube filled with ferrofluids. In the presence of MMF, stronger mode coupling could be achieved over the S-tapered fiber region. Its spectral response to variations in the applied MF intensity and ambient temperature have been investigated in detail. The proposed sensor shows a high MF sensitivity up to − 0.1130 d B / O e for the measurement range of 40 to 120 Oe, which, to our best knowledge, is higher than other previously reported MF sensors. And moreover, the measurement errors caused by temperature cross-sensitivity have been corrected by using a sensing matrix for the temperature range of 25°C to 35°C. Our proposed MF sensor possesses the advantages of high sensitivity, low cost, and applicability for applications in weak MF measurements.

Multimode optical fiber sensors: from conventional to machine learning-assisted

“…However, we can provide a few examples of widely utilized MMF sensors to illustrate the boundless applicability of MMF sensors. These include magnetic field sensing [112][113][114][115][116], distributed acoustic sensing [117], fluidic flow measurement [118], steel corrosion monitoring [119], relative humidity (RH) sensing [120][121][122], gas pressure sensing [103,123,124], and volatile organic compound (VOC) gas detection [125,126]. Table 6 provides a summary of the key parameters for the sensors discussed.…”

An Intensity-Demodulated Fiber-Optic Magnetometer Based on Nanostructured Magnetic Fluid-Filled Fluidic Photonic Crystal Fibers

“…For the sensor’s miniaturization and integration, intensity-modulated fiber-optic magnetometers are preferable. To realize intensity-demodulated magnetometers, Duan et al [ 15 ] reported a fiber-optic magnetometer based on x zcS-tapered and multimode fiber, whose sensitivity is up to 1.130 dB/mT in 4–12 mT. Lu et al [ 16 ] designed a fiber-optic magnetometer by using single serial-tilted-tapered fiber functionalized with magnetic fluid.…”