A fiber optic sensor measures a physical quantity by modulating the intensity, spectrum, phase, or polarization of light traveling through the optical fiber system. It's a device that converts light rays into electronic signals. Jose Miguel Lopez-Higuera: Handbook of Optical Fiber Sensing Technology, John Wiley & Sons, 2002. P 603 Radiation absorption excites an orbital electron to a higher energy level. Radiation absorption creates electronic excited states that are trapped by localized defects for extended periods of. This article explores the different types of Fiber Optic Sensors, their working principles, and various applications. Depending on the. Fiber Bragg gratings (FBGs) have, over the last few years, been used extensively in the telecommunication industry for dense wavelength division demultiplexing, dispersion compensation, laser stabilization, and erbium amplifier gain flattening. The basic working principle is that when the light signal passes through the optical fiber, parameters such as light intensity, wavelength, and phase will be affected by the. The fiber optic sensor has an optical fiber connected to a light source to allow for detection in tight spaces or where a small profile is beneficial. The optical fiber consists of the core and the cladding, which have different refractive indexes.