Ricchiuti, Amelia L.Barrera, D.Urrutia Azcona, AitorGoicoechea Fernández, JavierArregui San Martín, Francisco Javier2020-09-222020-09-222016A. L. Ricchiuti, D. Barrera, A. Urrutia, J. Goicoechea, F. J. Arregui and S. Sales, 'Continuous Liquid-Level Sensor Based on a Long-Period Grating and Microwave Photonics Filtering Techniques,' in IEEE Sensors Journal, vol. 16, no. 6, pp. 1652-1658, March15, 2016, doi: 10.1109/JSEN.2015.2504131.1558-174810.1109/JSEN.2015.2504131https://academica-e.unavarra.es/handle/2454/38219A fiber optic liquid-level sensor based on a long period grating (LPG) is proposed and experimentally validated. The principle of operation is based on a technique used to analyze microwave photonics filters. A 4-cm-long LPG cascaded with a high-reflectivity fiber Bragg grating is employed to achieve a continuous liquid-level sensor. The measurements have been performed using a modulator and a photo-detector with a modest bandwidth of less than 500 MHz, showing a sensitivity of -12.71 dB/cm and a standard deviation of 0.52 dB. One of the significant advantages of such sensing structure is that it is based on low-bandwidth radio frequency and off-the-shelf photonic components. In addition, the simple proposed scheme presents good repeatable performance and proves to be intrinsically robust against environmental changes, stable, and easy to reconfigure.7 p.application/pdfeng© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work.Fiber optic sensorsLiquid level sensorsLong period gratingsMicrowave photonics filtersContinuous sensorsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess