n this work, a preliminary study of the behavior of two different interferometric fiber optic sensors and two different wavelength selective fiber optic sensors is performed. A photonic crystal fiber Fabry-Pérot interferometer, a Sagnac interferometer, a commercial fiber Bragg grating (FBG) and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser are analyzed. A comparison of their sensitivities and resolutions is carried out to analyze their performance as sensors for cryogenic temperatures, taking into account their advantages and drawbacks. Keywords: cryogenic temperature, interferometric sensor, optical fiber sensor, random distributed feedback fiber lasers
In this work, a new application of random distributed feedback lasers to fiber optic sensing has been presented. The
particular properties of these lasers, such as the lack of longitudinal modes and high stability, have been exploited to
monitor transversal load using a phase-shifted fiber Bragg grating (PS-FBG), obtaining a resolution of 1g and a
sensitivity of 3.95GHz/Kg. Due to the PS-FBG birefringence and the load-interrelated transmission lines generated by
the PS-FBG along the orthogonal polarization directions, the beating of the two emission lines generated in the laser can
be monitored in the electrical domain. As a result, transversal load applied on the sensor can be measured.