López Aldaba, Aitor

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https://academica-e.unavarra.es/handle/2454/49427

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López Aldaba

First Name

Aitor

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Ingeniería Eléctrica y Electrónica

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750555

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810914

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Now showing 1 - 10 of 23

Open Access
Development of new punctual optical fiber transducer for sensing
(2018) López Aldaba, Aitor; López-Amo Sáinz, Manuel; Bariáin Aisa, Cándido; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The international research community has been nurturing photonic technologies over the years, aiming to develop cost effective solutions for a number of applications. Optical fibers offer an efficient solution for sensing and communication fields. Fiber optic sensors present appealing characteristics that make them very attractive when compared with conventional electric sensors such as immunity to electromagnetic interferences, as well as unfavorable environments, small size, ability for multiplexing and remote sensing. Another important aspect when using optical fibers is the ability to simultaneously use them as sensors and communication channels. The primary motivation for this PhD work was the study and development of new structures based in photonic crystal fibers. The main idea was to take advantage of the know-how of our group in fiber-optic communications and photonic sensing, as well as the recent advances in the sensing area to develop new structures based on the platform of photonic crystal fibers.
Open Access
Desarrollo de sensores en fibra de cristal fotónico para detección de gases y temperatura
(2014) López Aldaba, Aitor; López-Amo Sáinz, Manuel; Rodrigues Pinto, Ana Margarida; Rota Rodrigo, Sergio; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola Teknikoa; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Los sensores electromecánicos han sido durante décadas los transductores estándar para medir fenómenos físicos y mecánicos. Sin embargo estos sensores están limitados por las pérdidas en transmisión y la sensibilidad a las interferencias electromagnéticas, lo cual hace que su uso sea poco recomendable en ciertas aplicaciones. Una solución a estos problemas es la utilización de sensores de fibra óptica, ya que son inmunes a interferencias electromagnéticas, químicamente inertes, generalmente pasivos, ligeros, y cada vez tienen un menor coste. Este proyecto final de carrera, englobado dentro del proyecto europeo Ecoal-Mgt Gestión ecológica de pilas de residuos de carbón en combustión, programa SUDOE, tiene como objetivo el desarrollo experimental, caracterización, medida y optimización de sensores de fibra de cristal fotónico para medir temperatura y gases. Las fibras de cristal fotónico suponen una nueva oportunidad de estudio en el sensado de gases y líquidos, debido a su excepcional estructura formada por huecos. Estos huecos permiten a un fluido circular con libertad a lo largo de la fibra, lo cual modifica sus propiedades, además de permitir usar el campo evanescente para detectar y cuantificar la presencia de gas. Todo lo comentado anteriormente son las bases de este proyecto final de carrera, el cual se divide en dos etapas diferenciadas tanto por los materiales utilizados como pos sus objetivos. La primera parte se basa en el desarrollo experimental y optimización de un sensor de temperatura y de un sensor de tensión basados en fibras de cristal fotónico. La segunda parte consta de un estudio en detalle de tres fibras de cristal fotónico teóricamente aptas para su uso como sensor de gas. En este apartado se estudian las técnicas óptimas de manipulación y fusión de la fibra así como los resultados, sus causas y posibles alternativas. Finalmente se muestran las principales características del material utilizado y se realiza un estudio económico del proyecto final de carrera.
Open Access
Study of optical fiber sensors for cryogenic temperature measurements
(MDPI, 2017) Miguel Soto, Verónica de; Leandro González, Daniel; López Aldaba, Aitor; Beato López, Juan Jesús; Pérez de Landazábal Berganzo, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Fisika; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Física; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a -phase shifted fiber Bragg grating interrogated in In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser have been studied. Their sensitivities and resolutions as sensors for cryogenic temperatures have been compared regarding their advantages and disadvantages. Additionally, the results have been compared with the given by a commercial optical backscatter reflectometer that allowed for distributed temperature measurements of a single mode fiber.
Open Access
Title enhancement of the sensitivity of a volatile organic compounds MOF-sensor by means of its structure
(MDPI, 2017) López Torres, Diego; López Aldaba, Aitor; Elosúa Aguado, César; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Arregui San Martín, Francisco Javier; Ingeniaritza Elektrikoa eta Elektronikoa; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería Eléctrica y Electrónica; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this paper, we experimentally compare several core structures of Microstructured Optical Fibers (MOFs) for low-finesse Fabry-Pérot (FP) sensors. These sensors are designed for Volatile Organic Compounds (VOCs) measurements. We deposit Indium Tin Oxide (ITO) thin films by sputtering on the MOFs and different optical phase responses of the FP were measured for saturated atmospheres of ethanol. The sensitivity of the developed sensors is demonstrated to depend on the geometry and the dimensions of the MOF-cores. The sensors show recovery times under 100 s and the baselines are fully recovered after exposure to VOC.
Open Access
Experimental and numerical characterization of a hybrid Fabry-Perot cavity for temperature sensing
(MDPI, 2015) López Aldaba, Aitor; Rodrigues Pinto, Ana Margarida; López-Amo Sáinz, Manuel; Frazão, Orlando; Santos, José Luís; Baptista, José Manuel; Baierl, Hardy; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A hybrid Fabry-Pérot cavity sensing head based on a four-bridge microstructured fiber is characterized for temperature sensing. The characterization of this cavity is performed numerically and experimentally in the L-band. The sensing head output signal presents a linear variation with temperature changes, showing a sensitivity of 12.5 pm/°C. Moreover, this Fabry-Pérot cavity exhibits good sensitivity to polarization changes and high stability over time.
Open Access
Sensitivity optimization of a microstructured optical fiber ammonia gas sensor by means of tuning the thickness of a metal oxide nano-coating
(IEEE, 2019) López Torres, Diego; López Aldaba, Aitor; Elosúa Aguado, César; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this paper, the influence of the thickness of metallic-oxide coatings, ITO, and SnO2 on the sensitivity of a microstructured optical fiber Fabry–Pérot (FP) has been studied with the aim of developing ammonia gas fiber optic sensors. Also, the distribution of the optical power that can be coupled to the metallic-oxide sensing films is investigated in order to understand how the sensor’s sensitivity can be improved; the thickness of the coatings plays a relevant role on the sensitivity and response time. Films with thicknesses between 200 and 850 nm were experimentally examined resulting in an optimal thickness of 625 nm for a SnO2 film. The behavior of the sensors toward different concentrations of ammonia gas from 10 to 130 ppm was analyzed by measuring the phase shifts of the reflected signal using the fast Fourier transform of its optical spectrum. The registered response/recovery times of this sensor are below 90 s.
Open Access
Comparison between capacitive and microstructured optical fiber soil moisture sensors
(MDPI, 2018) López Aldaba, Aitor; López Torres, Diego; Campo-Bescós, Miguel; López Rodríguez, José Javier; Yerro Lizarazu, David; Elosúa Aguado, César; Arregui San Martín, Francisco Javier; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Landa Ingeniaritza eta Proiektuak; Institute of Smart Cities - ISC; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Ingeniería Eléctrica y Electrónica; Proyectos e Ingeniería Rural
Soil moisture content has always been an important parameter to control because it is a deterministic factor for site-specific irrigation, seeding, transplanting, and compaction detection. In this work, a discrete sensor that is based on a SnO2–FP (Fabry-Pérot) cavity is presented and characterized in real soil conditions. As far as authors know, it is the first time that a microstructured optical fiber is used for real soil moisture measurements. Its performance is compared with a commercial capacitive soil moisture sensor in two different soil scenarios for two weeks. The optical sensor shows a great agreement with capacitive sensor’s response and gravimetric measurements, as well as a fast and reversible response; moreover, the interrogation technique allows for several sensors to be potentially multiplexed, which offers the possibility of local measurements instead of volumetric: it constitutes a great tool for real soil moisture monitoring.
Open Access
Relative humidity multi-point optical sensors system based on Fast Fourier multiplexing technique
(SPIE, 2017) López Aldaba, Aitor; López Torres, Diego; Elosúa Aguado, César; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Arregui San Martín, Francisco Javier; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this paper, a new multipoint optical fiber system for relative humidity measurements based on Sn02-FP (Fabry-Pérot) sensing heads and an optical interrogator as single active device is presented and characterized. The interrogation of the sensing heads is carried out by monitoring the Fast Fourier Transform phase variations of the FP (Fabry-Pérot) interference frequencies. This method allows to multiplex several sensors with different wavelength spacing interference pattern. The sensors operate within a wide humidity range (20%-90% relative humidity) with low crosstalk between them. Five sensing heads have been measured using two different channels of the optical interrogator. The availability of four channels in the interrogator allows to multiplex a higher number of sensors, reducing proportionally the cost of each sensing point.
Open Access
SnO2-MOF-Fabry-Perot optical sensor for relative humidity measurements
(Elsevier, 2018) López Aldaba, Aitor; López Torres, Diego; Elosúa Aguado, César; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Arregui San Martín, Francisco Javier; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this paper, a new optical fiber sensor for relative humidity measurements is presented and characterized. The sensor is based on a SnO2 sputtering deposition on a microstructured optical fiber (MOF) low-finesse Fabry-Pérot (FP) sensing head. The feasibility of the device as a breathing sensor is also experimentally demonstrated. The interrogation of the sensing head is carried out by monitoring the Fast Fourier Transform phase variations of the FP interference frequency. This method substitutes the necessity of tracking the optical spectrum peaks or valleys, which can be a handicap when noise or multiple contributions are present: therefore, it is low-sensitive to noise and to artifacts signal amplitude. The sensor shows a linear behavior in a wide relative humidity range (20%–90% relative humidity) in which the sensitivity is 0.14 rad/%; the maximum observed instability is 0.007 rad, whereas the highest hysteresis is 5% RH. The cross correlation with temperature is also considered and a method to lower its influence is proposed. For human breathing measurement, the registered rising and recovery times are 370 ms and 380 ms respectively.
Open Access
Polyaniline deposition on tilted fiber Bragg grating for pH sensing
(SPIE, 2017) López Aldaba, Aitor; González Vila, Á.; Debliquy, M.; López-Amo Sáinz, Manuel; Caucheteur, C.; Lahem, D.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we present the results of a new pH sensor based on a polyaniline (PAni) coating on the surface of a tilted fiber Bragg grating. The pH-sensitive PAni was deposited by in situ chemical oxidative polymerization. The performance of the fabricated pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device. It was found that the sensor exhibits response to pH changes in the range of 2-12, achieving a sensitivity of 46 pm/pH with a maximum error due to the hysteresis effect of ±1.14 pH. The main advantages of this PAni-TFBG pH sensor are biochemical compatibility, temperature independence, long-term stability and remote real-time multipoint sensing features. This type of sensor could be used for biochemical applications, pipeline corrosion monitoring or remote-multipoint measurements.