Now showing items 1-7 of 7

    • Compensation of nonlocal effects induced by the extinction ratio of pump pulses in Brillouin optical time-domain analysis sensors 

      Mariñelarena Ollacarizqueta, Jon Upna; Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2019)   Artículo / Artikulua  OpenAccess
      We demonstrate a technique to compensate the nonlocal effects that appear in Brillouin optical time-domain analysis sensors when pump pulses with limited extinction ratio are deployed. These recently discovered nonlocal ...
    • Cyclic coding for Brillouin optical time-domain analyzers using probe dithering 

      Iribas Pardo, Haritz Upna; Loayssa Lara, Alayn Upna; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      We study the performance limits of mono-color cyclic coding applied to Brillouin optical time-domain analysis (BOTDA) sensors that use probe wave dithering. BOTDA analyzers with dithering of the probe use a dual-probe-sideband ...
    • 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 ...
    • Optimization in nanocoated D-shaped optical fiber sensors 

      Del Villar, Ignacio Upna; Zubiate Orzanco, Pablo Upna; Ruiz Zamarreño, Carlos Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      Nanocoated D-shaped optical fibers have been proven as effective sensors. Here, we show that the full width at half minimum (FWHM) of lossy mode resonance can be reduced by optimizing the nanocoating width, thickness and ...
    • Sensitivity enhancement in low cutoff wavelength long-period fiber gratings by cladding diameter reduction 

      Del Villar, Ignacio Upna; Partridge, Matthew; Rodríguez, Wenceslao; Fuentes, Omar; Socorro Leránoz, Abián Bentor Upna; Díaz Lucas, Silvia Upna; Corres Sanz, Jesús María Upna; James, Stephen; Tatam, Ralph (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The diameter of long-period fiber gratings (LPFGs) fabricated in optical fibers with a low cutoff wavelength was be reduced by hydrofluoric acid etching, enhancing the sensitivity to refractive index by more than a factor ...
    • Sensitivity optimization with cladding-etched long period fiber gratings at the dispersion turning point 

      Del Villar, Ignacio Upna; Cruz, José Luis; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      This work presents a refractive index sensor based on a long period fiber grating (LPFG) made in a reduced cladding fiber whose low order cladding modes have the turning point at large wavelengths. The combination of ...
    • Virtual FBGs using saturable absorbers for sensing with fiber lasers 

      Rodríguez Cobo, L.; Pérez Herrera, Rosa Ana Upna; Quintela, M. A.; Ruiz Lombera, Rubén; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      The spectral narrowing of Fiber Bragg Gratings (FBGs) introduced by unpumped Er-doped fiber (EDF) was analyzed for fiber lasers (FL). Owing to spatial hole burning (SHB), the spectral response of a virtual FBG can be ...