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. In remote sensing, fibers play a key role but based on the requirement, fibers may be used. Radiation absorption creates electronic excited states that are trapped by localized defects for extended periods of time. Heating the material enables the trapped states to interact with phonons and decay into lower-energy. As a sensing technology based on the principles of optical fiber, fiber optic sensors have gradually become key equipment in many industries due to their advantages, such as high precision, strong anti-interference, and long transmission distances. This article will explore the working principle. A fiber-optic sensor is a sensor that uses optical fiber either as the sensing element ("intrinsic sensors"), or as a means of relaying signals from a remote sensor to the electronics that process the signals ("extrinsic sensors").
[PDF Version]