SMF-MMF-SCF-Based Humanoid-Shaped Fiber-Optic Sensor for Wide Range of Magnetic Field Detection

In this study, we propose a fiber-optic magnetic field sensor based on a humanoid fiber structure. Considering that conventional magnetic field sensors are susceptible to electromagnetic interference, in this study we employed a fiber optic fusion splicer and a combiner manufacturing system (CMS) to fabricate a single-mode fiber (SMF), a multimode fiber (MMF), and a seven-core fiber (SCF) fused humanoid fiber optic sensor. Also, this study measured the magnetic field strength by coating the fiber optic sensing region with nickel ferrate (NiFe2O $_{{4}}\text {)}$ and using the ferromagnetic nature of nickel group compounds. We performed a series of additional tests to assess the sensitivity, accuracy, and reproducibility of our fabricated humanoid fiber structure. Various experimental tests demonstrated that the sensitivity and accuracy of the humanoid fiber optic sensors were 1.1 pm/mT and 0.957, respectively, in an increasing magnetic field, and 0.5 pm/mT and 0.9619, respectively, in a decreasing magnetic field. The magnetic field sensor has proven to be very precise, capable of real-time monitoring, compact in size, and able to measure with minimal loss. As a result, the magnetic field sensor is highly advantageous in healthcare monitoring and geological surveys because of its exceptional accuracy, real-time monitoring capability, compact size, and noninvasive measurement.