Optical Fiber Sensor Systems

The development of high-quality and low-cost optical fibers for telecommunication applications has also inspired the rapidly growing field of fiber-optical sensors. For such fiber sensors, a distinction can be made between intrinsic concepts, where the fiber itself serves as a sensitive element, and extrinsic concepts, where the fiber serves only as an optical communication link. Generally, all optical parameters defining the state of light such as amplitude, phase, wavelength or polarization can be used for measuring an external physical quantity via an optical fiber sensor. In addition, such sensors make it possible to exploit general advantages of optical fibers such as small size and weight, immunity against electromagnetic radiation, electrically insulating properties (e.g. for high voltage applications), or applicability under adverse environmental conditions. An overview on such fiber sensor concepts with a focus on spectrally encoding fiber sensors will be given.