Beyond the Spectrum: Specialty Optical Fibers in Magnetic Field Sensing

This chapter explores the advancements in magnetic field sensors based on optical fibers and advanced multi-material fibers. Traditional optical fibers face challenges in directly sensing magnetic fields due to their insulating properties against electromagnetic interference. To overcome this limitation, transduction materials and modified structures are employed, enabling the conversion of magnetic fields into measurable changes such as optical fiber’s stress or refractive index. The chapter delves into magneto-active materials like magneto-fluidicMagneto-fluidic, magneto-strictiveMagneto-strictive, and magneto-optical materials. It also discusses the structures for enhancing sensitivity, including micron fibers, optical fiber gratings, and interferometers. Types of fiber-based magnetometers have been extended to multi-material multi-functional fibersMulti-material multi-functional fibers with recent advances, particularly those drawn through thermal drawing processesThermal drawing processes. Novel designs to integrate magneto-active material and commercial microchips within the silica and polymer fibers, showcase potential advancements in distributed sensingDistributed sensing. The chapter presents notable studies, demonstrating diverse applications such as high-sensitivity magnetic field imaging, environmental monitoring for geophysical exploration, and industrial applications in equipment monitoring. The evolving landscape of fiber-shaped magnetic field sensors promises enhanced capabilities and broader applications across industries.