Fiber-Optic Magnetic Field Sensor Based on Four-Tapered-In-Tapered Structure

In this article, we designed a fiber optic device sensor that features a unique structure consisting of four tapers. This structure, known as the tapered-in-tapered (TIT) optical fiber structure, was developed using an advanced combiner manufacturing system (CMS). We conducted a performance comparison between a fiber optic sensor equipped with magnetic graphene oxide (MGO) and MGO/
${\text {NiFe}}_{{2}}\text {O}_{{4}}$
-coated. We used a spectrometer to measure the peak wavelengths while examining the optical field under different magnetic field strengths. Using a spectrometer, we recorded the peak wavelengths observed when optical field was exposed to various magnetic field strengths. The fiber optic sensors coated with MGO alone exhibited sensitivity of 1.5 pm/mT and accuracy of 0.96277 in the forward magnetic field and sensitivity of 1.2 pm/mT and accuracy of 0.97817 in the reverse magnetic field within the detection range of 5–600 mT. Meanwhile, the fiber optic sensors coated with both MGO and
${\text {NiFe}}_{{2}}\text {O}_{{4}}$
exhibited sensitivity of 0.7 pm/mT and accuracy of 0.98234 in the forward magnetic field and sensitivity of 0.4 pm/mT and accuracy of 0.99794 in the reverse magnetic field. This new fiber-optic magnetic field sensor boasts a compact design, exceptional interference immunity, remarkable sensitivity, and the ability to be reused. Fiber optic magnetic field sensors have found extensive applications in various industries such as industrial manufacturing, medical research, and national security. Their widespread use is crucial for advancing scientific, technological, and social advancements.