Fiber optic proximity sensors are used to detect the proximity of target objects using light. Light is supplied and returned via fiber optic cables. 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"). Fibers have many uses in remote sensing. They can detect very small objects, are particularly flexible to mount and are extremely resistant in harsh environments – even in high temperatures. 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 time. Heating the material enables the trapped states to interact with phonons and decay into lower-energy. A Fiber Sensor is a type of Photoelectric Sensor that enables detection of objects in narrow locations by transmitting light from a Fiber Amplifier Unit with a Fiber Unit. In essence, a sensor reacts to a physical, chemical, or biological condition.
