The light source illuminates the sample, the fiber optic cable transmits the light to the spectrometer, the diffraction grating separates the light into different wavelengths, and the detector captures and analyzes the light intensity at each wavelength. These devices utilize the unique properties of fiber optics to measure and analyze the spectral composition of light, making them indispensable tools in. We present here the recent advance in exploring new detection mechanisms, materials, processes, and applications of fiber optic sensors. Introduction In this Special Issue, we aim to focus on all aspects of the recent. Electromagnetism and Telecom Department, University of Mons, 7000 Mons, Belgium Foundation for Research and Technology Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), 70013 Heraklion, Greece School of Sciences, European University Cyprus/EUC Research Centre, 1516 Nicosia, Cyprus. Fiber optic spectrometer is a commonly used type of spectrometer, which has the advantages of high sensitivity, easy operation, flexible use, good stability and high accuracy. Optical fibers provide unparalleled flexibility, allowing critical optical components to be positioned conveniently and securely, even in complex industrial setups. How does NLIR revolutionize MIR.