Now showing items 1-20 of 23

    • BOTDA measurements tolerant to non-local effects by using a phase-modulated probe wave and RF demodulation 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      We demonstrate a Brillouin optical time domain analysis sensor based on a phase modulated probe wave and RF demodulation that provides measurements tolerant to frequency dependent variations of the pump pulse power induced ...
    • Brillouin optical time-domain analysis sensor assisted by Brillouin distributed amplification of pump pulses 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      We demonstrate the extension of the measurement range of Brillouin optical time-domain analysis (BOTDA) sensors using a distributed Brillouin amplifier (DBA). The technique is based on injecting a DBA pump wave in the ...
    • Brillouin optical time-domain analysis sensor with pump pulse amplification 

      Mompó Roselló, Juan José Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensors with mitigation for pump pulse attenuation. The technique is based on operating the sensor in loss configuration so ...
    • 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 ...
    • Detrimental effects in Brillouin distributed sensors caused by EDFA transient 

      Feng, Cheng; Iribas Pardo, Haritz Upna; Mariñelarena Ollacarizqueta, Jon Upna; Schneider, Thomas; Loayssa Lara, Alayn Upna (Optical Society of AmericaIEEE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We investigate the deleterious effect and the error in Brillouin optical time-domain analyzers induced by the combination of a low extinction ratio pulse generation with the transient behavior of erbium-doped fiber amplifiers.
    • Dynamic BOTDA measurements based on Brillouin phase-shift and RF demodulation 

      Urricelqui Polvorinos, Javier Upna; Zornoza Indart, Ander; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2012)   Artículo / Artikulua  OpenAccess
      We demonstrate a novel dynamic BOTDA sensor based, for the first time to our knowledge, on the use of the Brillouin phase shift in addition to the conventional Brillouin gain. This provides the advantage of measurements ...
    • Egituren egoeraren monitorizaziorako zuntz optikoan oinarritutako sentsore sinplifikatua 

      Iribas Pardo, Haritz Upna; Sagüés García, Mikel Upna; Mariñelarena Ollacarizqueta, Jon Upna; Loayssa Lara, Alayn Upna (Udako Euskal Unibertsitatea, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Brillouin hedatuko denbora eremu optikoaren analisian (BOTDA) oinarritutako sentsoreak, estruktura handien (100 km luzerako estrukturak) deformazioa eta tenperatura neurtzeko gaitasuna dute. Lan honetan, BOTDA konfigurazio ...
    • Fringe generation with non-uniformly coated long-period fiber gratings 

      Del Villar, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna; Cusano, Andrea; Paladino, Domenico; Cutolo, Antonello (Optical Society of America, 2007)   Artículo / Artikulua  OpenAccess
      In this work, the spectral characteristics of non-uniform symmetrically ring shaped coatings deposited on long-period fiber gratings (LPFGs) have been theoretically and experimentally investigated. To optimize the ...
    • 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 ...
    • Latest research on long-range Brillouin distributed sensing 

      Loayssa Lara, Alayn Upna; Urricelqui Polvorinos, Javier Upna; Iribas Pardo, Haritz Upna; Mariñelarena Ollacarizqueta, Jon Upna; Mompó Roselló, Juan José Upna (SPIE, 2019)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We review the latest developments in long-range Brillouin optical time-domain analysis sensors. The factors that impair the performance of these sensors, particularly in terms of their distance range, are discussed together ...
    • Mode transition in complex refractive index coated single-mode–multimode–single-mode structure 

      Socorro Leránoz, Abián Bentor Upna; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      By coating a single-mode–multimode–single-mode (SMS) structure with a high refractive index thin-film it is possible to obtain a transition of modes for specific combinations of thin-film thickness, thinfilm refractive ...
    • 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 ...
    • Phasorial differential pulse-width pair technique for long-range Brillouin optical time-domain analysis sensors 

      Urricelqui Polvorinos, Javier Upna; Sagüés García, Mikel Upna; Loayssa Lara, Alayn Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      We introduce a novel phasorial differential pulse width pair (PDPP) method for Brillouin optical time domain analysis (BOTDA) sensors that combines spatial resolution enhancement with increased tolerance to non local ...
    • Refractometric sensors based on multimode interference in a thin-film coated singlemode– multimode–single-mode structure with reflection configuration 

      Del Villar, Ignacio Upna; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      Thin-film coated single-mode–multimode–single-mode (SMS) structures have been analyzed both theoretically and experimentally with the aim of detecting different refractive indices. By adequate selection of the thickness ...
    • Second-order non-local effects mitigation in BOTDA sensors by tracking the BFS profile 

      Mompó Roselló, Juan José Upna; Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (SPIE, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      We demonstrate a technique to mitigate the residual second-order non-local effects in Brillouin optical time-domain analysis (BOTDA) sensors in which the Brillouin frequency shift (BFS) profile is not uniform along the ...
    • Second-order nonlocal effects mitigation in Brillouin optical time-domain analysis sensors by tracking the Brillouin frequency shift profile of the fiber 

      Mompó Roselló, Juan José Upna; Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Loayssa Lara, Alayn Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      We report on an additional limitation that has been found in Brillouin optical time-domain analysis (BOTDA) sensors due to the so-called second-order nonlocal effects (NLE). Second-order NLE appear in BOTDA setups that ...
    • 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 ...
    • Spectral evolution with incremental nanocoating of long period fiber gratings 

      Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Achaerandio, Miguel Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2006)   Artículo / Artikulua  OpenAccess
      The incremental deposition of a thin overlay on the cladding of a long-period fiber grating (LPFG) induces important resonance wavelength shifts in the transmission spectrum. The phenomenon is proved theoretically with ...