Open Access
SnO2 based optical fiber refractometers
(SPIE, 2012) Sánchez Zábal, Pedro; Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
In this work, the fabrication and characterization of refractometers based on lossy mode resonances (LMR) is presented. Tin dioxide (SnO2) films deposited on optical fibers are used as the LMR supporting coatings. These resonances shift to the red as a function of the external refractive index, enabling the fabrication of robust and highly reproducible wavelength-based optical fiber refractometers. The obtained SnO2-based refractometer shows an average sensitivity of 7198 nm/refractive index unit (RIU) in the range 1.333-1.420 RIU.
Open Access
Optical fiber sensors based on indium tin oxide surface plasmon resonance supporting coatings
(SPIE, 2009-10-05) Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, surface plasmon resonance (SPR) based optical fiber sensors are revisited by using a transparent conductive coating, Indium Tin Oxide in our case, as the SPR supporting layer. The utilization of these coatings shifts the plasmon resonance band to the infra-red region and allows the tunability of the SPR wavelength by adjusting the film fabrication parameters. Here, we study the fabrication process of these novel devices and characterize their response to variations in the refractive index of the external medium opening the door to a wide range of applications.
Open Access
Generation of lossy mode resonances with absorbing thin-films
(IEEE, 2010) Del Villar, Ignacio; Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The generation of lossy mode resonances with absorbing thin-films is analyzed with electromagnetic theory. The main differences with surface plasmon resonances are presented and some rules are given towards an optimum design of sensing devices based on absorbing thin-film coated silica substrates. The material selected for the absorbing thin-film is ITO, which is adequate for supporting both surface plasmon resonances and lossy mode resonances.
Open Access
Resonances in coated long period fiber gratings and cladding removed multimode optical fibers: a comparative study
(Optical Society of America, 2010) Del Villar, Ignacio; Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Two optical fiber devices have been coated in parallel: a long period fiber grating (LPFG) and a cladding-removed multimode optical fiber (CRMOF). The progressive coating of the LPFG by means of the layer-by-layer electrostatic-self-assembly, permits to observe a resonance wavelength shift of the attenuation bands in the transmission spectrum. The cause of this wavelength shift is the reorganization of the cladding mode effective indices. The cause of this modal reorganization can be understood with the results observed in the CRMOF coated in parallel. A lossy-moderesonance (LMR) is generated in the same wavelength range of the LPFG attenuation bands analyzed. Moreover, the thickness range where the wavelength shift of the LPFG attenuation bands occurs coincides exactly with the thickness range where the LMR can be visualized in the transmission spectrum. These phenomena are analyzed theoretically and corroborated experimentally. The advantages and disadvantages of both optical fiber devices are explained.
Open Access
Quantum dots coatings inside photonic crystal fibers for temperature sensing
(IEEE, 2008-12-16) Arigita Lasheras, Jesús; Larrión Zabaleta, Beatriz; Bravo Larrea, Javier; Hernáez Sáenz de Zaitigui, Miguel; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Gobierno de Navarra / Nafarroako Gobernua
Temperature sensors based on Quantum Dots (QDs) nanofilms deposited on the inner holes of a Photonic Crystal Fiber (PCF) was created using the layer by layer electrostatic self-assembly method. The structure is based on a PCF fiber segment spliced between two Standard Multimode Fibers (MMF) of different diameters. The sensors showed a linear variation of the intensity and wavelength emission for a temperature range from -20 ºC to 70 ºC.
Open Access
Generation of lossy mode resonances by deposition of high-refractive-index coatings on uncladded multimode optical fibers
(IOP Publishing Ltd, 2010) Del Villar, Ignacio; Ruiz Zamarreño, Carlos; Sánchez Zábal, Pedro; Hernáez Sáenz de Zaitigui, Miguel; Fernández Valdivielso, Carlos; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A comparative study of lossy mode resonances generated by depositing two different materials is presented. The two materials selected are indium tin oxide (ITO) and indium oxide. The two materials present different dielectric dispersion, which leads to the generation of single-peak lossy mode resonances with the ITO coated optical fibers and dual-peak lossy mode resonances with the In2O3 coated optical fibers. The obvious advantage of a dual-peak based measurement in the sensors field is enhanced by a sensitivity increase observed in sensors based on In2O3 if compared with those based on ITO. These characteristics are analyzed both theoretically and experimentally.
Open Access
Photonic crystal fiber temperature sensor based on quantum dot nanocoatings
(Hindawi / Wiley, 2009) Larrión Zabaleta, Beatriz; Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Goicoechea Fernández, Javier; Bravo Larrea, Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Quantum dot nanocoatings have been deposited by means of the Layer-by-Layer technique on the inner holes of Photonic Crystal Fibers (PCFs) for the fabrication of temperature sensors. The optical properties of these sensors including absorbance, intensity emission, wavelength of the emission band, and the full width at half maximum (FWHM) have been experimentally studied for a temperature range from -40 to 70ºC.
Open Access
Optical fiber refractometers based on indium tin oxide coatings with response in the visible spectral region
(Elsevier, 2011) Ruiz Zamarreño, Carlos; López, S.; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
This work presents the fabrication of optical fiber refractometers based on indium tin oxide (ITO) coatings with response in the visible spectral region. ITO thin-films have been sputtered by employing a rotating mechanism that enables the fabrication of smooth homogeneous coatings onto the optical fiber core. The ITO coated optical fiber devices present several resonances in the visible and infra-red region. These resonances show high optical power attenuations (more than 10 dB) in the visible spectral region, which produces changes in the colour of the output visible light. Therefore, since these resonances shift as a function of the surrounding medium refractive index (SMRI), it is feasible to determine the refractive index of the outer medium in contact with the ITO coating by simply monitoring the chromatic coordinates of the visible output light.
Open Access
Fiber-optic pH sensors fabrication based on selective deposition of neutral red
(IEEE, 2009-01-22) Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ruiz Zamarreño, Carlos; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a novel application of the electric field directed layer-by-layer self assembly (EFDLA) selective deposition method for the fabrication of optical fiber pH sensors is presented. Here, indium tin oxide (ITO) coated optical fibers have been fabricated via a dip-coating deposition method. These fibers are used as electrodes in the EFDLA protocol in order to deposit selectively the sensitive layer. Neutral Red (NR) colorimetric pH sensitive indicator and the polymers poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) are used in order to obtain a pH sensitive nanostructured coating onto ITO coated optical fibers. The results obtained in this work revealed that the LbL material adsorption on the electrodes can be enhanced or even inhibited when applying a specific direct current voltage between them under some other specific fabrication parameters. Particularly, the response of these sensors to variations of the pH in the surrounding medium was studied when the pH of the solutions used for the fabrication of the films was adjusted to 7.0 and the potential applied between electrodes was set to 2.5 V. These sensors showed fast response time and high repeatability.
Open Access
Design rules for lossy mode resonance based sensors
(Optical Society of America, 2012) Del Villar, Ignacio; Hernáez Sáenz de Zaitigui, Miguel; Ruiz Zamarreño, Carlos; Sánchez Zábal, Pedro; Fernández Valdivielso, Carlos; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
Lossy mode resonances can be obtained in the transmission spectrum of cladding removed multimode optical fiber coated with a thin-film. The sensitivity of these devices to changes in the properties of the coating or the surrounding medium can be optimized by means of the adequate parameterization of the coating refractive index, the coating thickness and the surrounding medium refractive index (SMRI). Some basic rules of design, which enable the selection of the best parameters for each specific sensing application, are indicated in this work.