López Aldaba, AitorLópez Torres, DiegoElosúa Aguado, CésarAuguste, Jean-LouisJamier, RaphaelRoy, PhilippeArregui San Martín, Francisco JavierLópez-Amo Sáinz, Manuel2019-09-162019-09-162017A. Lopez-Aldaba, D. Lopez-Torres, C. Elosua, J.-L. Auguste, R. Jamier, P. Roy, F. J. Arregui, and M. Lopez-Amo "Relative humidity multi-point optical sensors system based on fast Fourier multiplexing technique", Proc. SPIE 10323, 25th International Conference on Optical Fiber Sensors, 103233L (23 April 2017); https://doi.org/10.1117/12.22651740277-786X10.1117/12.2265174https://academica-e.unavarra.es/handle/2454/34852In this paper, a new multipoint optical fiber system for relative humidity measurements based on Sn02-FP (Fabry-Pérot) sensing heads and an optical interrogator as single active device is presented and characterized. The interrogation of the sensing heads is carried out by monitoring the Fast Fourier Transform phase variations of the FP (Fabry-Pérot) interference frequencies. This method allows to multiplex several sensors with different wavelength spacing interference pattern. The sensors operate within a wide humidity range (20%-90% relative humidity) with low crosstalk between them. Five sensing heads have been measured using two different channels of the optical interrogator. The availability of four channels in the interrogator allows to multiplex a higher number of sensors, reducing proportionally the cost of each sensing point.4 p.application/pdfeng© 2017 SPIE. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, or modification of the contents of the publication are prohibited.Photonic crystal fiberMicrostructured optical fiberSputteringFiber sensorHumidity sensingFast Fourier transformMultiplexinginfo:eu-repo/semantics/conferenceObjectinfo:eu-repo/semantics/openAccess