In this chapter, a temperature sensor is demonstrated based on four different techniques; intensity modulated fiber optic displacement sensor (FODS), lifetime measurements, microfiber loop resonator (MLR) and stimulated brillouin scattering. Fiber Bragg gratings are very efficient at temperature sensing and are easy to implement; however, they always need additional techniques to discriminate the Bragg shifts by temperature and by strain/compression and they also require expensive phase-masks. Fiber-Bragg-Gratings (FBGs) are used for spot sensing, whereas Rayleigh, Brillouin and Raman scattering are used for distributed sensing in long fibers. This is done by adding a periodic variation to the refractive index of the fiber core. ▪ One of the main advantages of this technology is its iiiiintrinsic.
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