The advantages of distributed fiber optic sensors can be attributed to the fact that the whole fiber acts as a sensor itself. One can think of them as thousands of sensors integrated within one fiber system. Optical fibers being cheap, light, pliable and immune to electromagnetic interference, makes distributed sensors effective, flexible and inert systems. The distinctive property of such sensors is their spatial resolution for simultaneous measurements along the entire length of the sensing fiber. This can be used extensively in measurement of temperature, pressure, strain, current, chemical concentration. Distributed fiber optic sensors find many applications in geotechnical, medical, military, construction, scientific and other fields.