What is a fiber optic sensor?

Fiber optic sensor:

A fiber optic sensor is a sensor which uses optical fiber either like the sensing tool ("intrinsic sensors"), or implies as of relaying signals through a remote sensor to the electronics which process the signals ("extrinsic sensors"). Fibers have several uses into remote sensing. Depending onto the application, fiber may be used due to its small size, or the fact which no electrical power is required at the remote location, or since many sensors can be multiplexed beside the length of a fiber by utilizing different wavelengths of light for every sensor, or by sensing the time delay as light passes beside the fiber by each sensor. There time delay can be finding using a device as like an optical time-domain reflectometer.