• Fabrication of Bragg gratings on the end facet of standard optical fibers by sputtering the same material 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; del Villar, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (IEEE, 2016)   Artículo / Artikulua  OpenAccess
      A sputtering process has been applied to deposit quarter-wavelength stacks on the end facet of cleaved optical fibers by using only one sputtering target. Standard multimode optical fibers were used as substrates to fabricate ...
    • High sensitivity humidity sensor based on cladding-etched optical fiber and lossy mode resonances 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      In this work a high sensitivity optical fiber humidity sensor (OFHS) is presented. The configuration chosen for this purpose is a cladding-etched single mode optical fiber (CE-SMF) coated with a thin film of tin oxide ...
    • Humidity sensor based on Bragg gratings developed on the end facet of an optical fiber by sputtering of one single material 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the ...
    • Micro and nanostructured materials for the development of optical fibre sensors 

      Elosúa Aguado, César Upna; Arregui San Martín, Francisco Javier Upna; Del Villar, Ignacio Upna; Ruiz Zamarreño, Carlos Upna; Corres Sanz, Jesús María Upna; Bariáin Aisa, Cándido Upna; Goicoechea Fernández, Javier Upna; Hernáez Sáenz de Zaitigui, Miguel Upna; Rivero Fuente, Pedro Upna; Socorro Leránoz, Abián Bentor Upna; Urrutia Azcona, Aitor Upna; Sánchez Zábal, Pedro Upna; Zubiate Orzanco, Pablo Upna; López Torres, Diego Upna; Acha Morrás, Nerea de Upna; Ascorbe Muruzabal, Joaquín Upna; Ozcariz Celaya, Aritz Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The measurement of chemical and biomedical parameters can take advantage of the features exclusively offered by optical fibre: passive nature, electromagnetic immunity and chemical stability are some of the most relevant ...
    • Nanofabrication of phase-shifted Bragg gratings on the end facet of multimode fiber towards development of optical filters and sensors 

      Gallego, E.E.; Ascorbe Muruzabal, Joaquín Upna; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Elsevier, 2018)   Artículo / Artikulua
      This work describes the process of nanofabrication of phase-shifted Bragg gratings on the end facet of a multimode optical fiber with a pulsed DC sputtering system based on a single target. Several structures have been ...
    • Recent developments in fiber optics humidity sensors 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      A wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical ...