The applications of fiber optic sensors are vast and cover many fields, including industry, medical care, transportation, and environmental monitoring. It's a device that converts light rays into electronic signals. Think of it like a photoresistor, which changes its resistance based. Fiber optic sensors—also known as optical fiber sensors—use optical fibers either as the sensing element or as a medium to transmit sensing signals. 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. Intensity, phase, and wavelength based fiber optic sensors are the most widely used sensors.