Ascorbe Muruzabal, JoaquínFuentes Lorenzo, OmarArregui San Martín, Francisco JavierMatías Maestro, IgnacioCorres Sanz, Jesús María2021-03-182021-08-112020J. Ascorbe, O. Fuentes, F. J. Arregui, I. R. Matias and J. M. Corres, 'Optical fiber vacuum sensor based on etched SMS structure and PDMS coating,' in IEEE Sensors Journal, doi: 10.1109/JSEN.2020.3015577.1558-1748 (Electronic)10.1109/JSEN.2020.3015577https://academica-e.unavarra.es/handle/2454/39418In this work, an optical fiber vacuum sensor based on a single-mode multimode single-mode (SMS) structure coated with polydimethylsiloxane (PDMS) is studied. The SMS structure generates an interferometric pattern based on multimode interference. The structure is dip-coated with a layer of PDMS, whose optical properties change when it is subjected to varying vacuum pressure. Different strategies are applied in an attempt to improve the final performance of the sensor, such as decreasing the diameter of the fiber and modifying the properties of the coating by modifying the proportion of solvent. Decreasing the diameter of the optical fiber and using toluene as a solvent are both proved to be successful strategies for increasing the sensitivity of the sensor. The devices are studied in the 1×10-3–10 mbar range with a maximum wavelength shift of 12 nm, leading to a maximum sensitivity of 35 nm/mbar. The simplicity of the fabrication process, which can be applied to more sensitive structures, suggests that PDMS may be a good choice for the development of optical fiber vacuum sensors.8 p.application/pdfeng© 2020 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.Optical fiberModal interferometerVacuum sensorPolydimethylsiloxanePDMSinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess