San Fabián García, NoéSocorro Leránoz, Abián BentorDel Villar, IgnacioDíaz Lucas, SilviaMatías Maestro, Ignacio2020-06-052020-06-072019N. S. Fabián, A. B. Socorro-Leránoz, I. D. Villar, S. Díaz and I. R. Matías, 'Multimode-Coreless-Multimode Fiber-Based Sensors: Theoretical and Experimental Study,' in Journal of Lightwave Technology, vol. 37, no. 15, pp. 3844-3850, 1 Aug.1, 2019, doi: 10.1109/JLT.2019.2921609.0733-872410.1109/JLT.2019.2921609https://academica-e.unavarra.es/handle/2454/37097This paper presents a complete study on the spectral behavior of a multimode-coreless-multimode fiber-optic structure, as well as its application as a refractometer and a liquid level sensor. The combination of two standard multimode fibers fused to a coreless fiber segment allows generating narrow interferometric bands in the optical spectrum, whose sensitivity can be improved by an adequate selection of the dimensions of the device (the coreless segment length and the diameter of the sensing area). A second way to improve the performance of the device is to deposit a thin film of SnO2, which allows increasing the sensitivity up to 314 nm/RIU. This widens the number of applications where this structure can be used. As an example, a liquid level sensor with 0.73 nm/mm sensitivity is presented.7 p.application/pdfeng© 2019 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.InterferometerMultimode-coreless-multimode (MCM)Optical fiber sensorRefractive indexRefractometerWater level sensorinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess