Study of optical fiber sensors for cryogenic temperature measurements

In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a -phase shifted fiber Bragg grating interrogated in In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser have been studied. Their sensitivities and resolutions as sensors for cryogenic temperatures have been compared regarding their advantages and disadvantages. Additionally, the results have been compared with the given by a commercial optical backscatter reflectometer that allowed for distributed temperature measurements of a single mode fiber.Financial support from the Spanish Comisión Interministerial de Ciencia y Tecnología within projects TEC2013-47264-C2-2-R and TEC2016-76021-C2-1-R, Innocampus, Cost action MP1401 and the FEDER funds is acknowledged. Also the support of the Institute of Smart Cities by means of a postdoctoral fellowship