Open Access
Quasi-distributed vibration sensing using OFDR and weak reflectors
(Optical Society of America, 2019) Zhu, Mengshi; Leandro González, Daniel; López-Amo Sáinz, Manuel; Murayama, Hideaki; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The authors proposed a quasi-distributed vibration sensing technique using in-line weak reflectors and optical frequency domain reflectometry (OFDR). As a result, they achieved an 8 kHz measurable vibration frequency with a 15-20 cm spatial resolution employing a low repetition rate (similar to 8 Hz). Moreover, a measurable frequency of 30 kHz was achieved for a 1.5 m spatial resolution. The ability of the system to determine the frequency and amplitude of several sections vibrating simultaneously is evaluated for different configurations. Because of the simple arrangement, high detectable frequency, and high sensitivity, this approach is expected to be especially well suited for mechanical vibration sensing applications, particularly in medium-sized structures.
Open Access
High sensitive micro-displacement intensity fiber sensor by using a multiwavelength erbium doped fiber ring laser based on optical add-drop multiplexers
(SPIE, 2014-06-02) Pérez Herrera, Rosa Ana; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a wavelength division multiplexed fiber ring laser, based on optical add-drop multiplexers to interconnect intensity sensors has been experimentally demonstrated. Three different laser lines were obtained simultaneously all with an optical signal to noise ratio higher than 30dB. This proposed configuration is based on commercial devices and is adapted to the ITU channels normative. By using this configuration each sensor was associated with a different wavelength directly offered by each OADM and a reference wavelength was also included in order to distinguish between power variations induced by the transducer or to detect a fiber failure. This sensor system has been experimentally verified by using microbending sensors obtaining experimental slope sensitivity as good as -0.327dB/µm.
Open Access
Multiplexación de sensores remotos mediante estructuras láser de fibra óptica
(2010) Leandro González, Daniel; López-Amo Sáinz, Manuel; 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
En este proyecto final de carrera se desarrolla en primer lugar una red de sensores remota para larga distancia utilizando ganancia Raman y Brillouin. El sistema se basa en un láser de fibra con sensores FBG remotos, realizándose la medida en el medio eléctrico mediante heterodinaje. Se alcanzan inicialmente 100 km con cuatro sensores conectados en serie. Esa distancia finalmente se aumenta hasta los 155 km donde también se incluye amplificación mediante fibra dopada con erbio. Todo este estudio desemboca en el diseño de un sistema de medida y el estudio de los diferentes problemas que surgen en la interrogación a larga distancia. En la segunda parte del proyecto se estudia un láser de fibra de dos líneas en régimen monomodo con configuración en anillo y amplificación mediante fibra dopada con erbio. Se basa en un montaje ya conocido, sobre el cual se realizan numerosas pruebas y modificaciones. Los resultados obtenidos se estudian y analizan para buscar las causas de la operación en régimen monomodo del sistema. Finalmente se realiza un estudio económico del proyecto final de carrera y se muestran las principales características del material utilizado.
Open Access
Medida de torsión en seguidores solares con sensores de fibra óptica
(SEDOPTICA, 2021) Leandro González, Daniel; Bravo Acha, Mikel; López-Amo Sáinz, Manuel; Loayssa Lara, Alayn; Júdez Colorado, Aitor; Mariñelarena Ollacarizqueta, Jon; Falcone Lanas, Francisco; Jiménez Romero, Sergio; Moriana García, Iñaki; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua WINDSOLAR (0011-1365-2017-000122)
En este trabajo se ha monitorizado la torsión sufrida por una estructura de seguidores solares empleando sensores de fibra óptica. Estas medidas de campo se han obtenido con una red de sensores formada por 45 redes de difracción de Bragg en una huerta solar activa. Estos resultados, correlados con la velocidad y dirección del viento permitirían aumentar la eficiencia de los seguidores y ayudar a entender y prevenir efectos negativos relacionados con inestabilidades aeroelásticas.
Open Access
Interferometric vs wavelength selective optical fiber sensors for cryogenic temperature measurements
(SPIE, 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; Ingeniería Eléctrica y Electrónica; Física
In this work, a preliminary study of the behavior of two different interferometric fiber optic sensors and two different wavelength selective fiber optic sensors is performed. A photonic cristal fiber Fabry-Pérot interferometer, a Sagnac interferometer, a commercial fiber Bragg grating (FBG) and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser are analyzed. A comparison of their sensitivities and resolutions is carried out to analyze their performance as sensors for cryogenic temperatures, taking into account their advantages and drawbacks.
Open Access
High-resolution transversal load sensor using a random distributed feedback fiber laser
(SPIE, 2016) Miguel Soto, Verónica de; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a new application of random distributed feedback lasers to fiber optic sensing has been presented. The particular properties of these lasers, such as the lack of longitudinal modes and high stability, have been exploited to monitor transversal load using a phase-shifted fiber Bragg grating (PS-FBG), obtaining a resolution of 1g and a sensitivity of 3.95GHz/Kg. Due to the PS-FBG birefringence and the load-interrelated transmission lines generated by the PS-FBG along the orthogonal polarization directions, the beating of the two emission lines generated in the laser can be monitored in the electrical domain. As a result, transversal load applied on the sensor can be measured.
Open Access
In-field torsion measurements on solar trackers using fiber optic sensors
(Optica, 2020) Leandro González, Daniel; Bravo Acha, Mikel; Júdez Colorado, Aitor; Mariñelarena Ollacarizqueta, Jon; Falcone Lanas, Francisco; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; Jiménez, S.; Achaerandio, Álvaro; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Gobierno de Navarra / Nafarroako Gobernua
In-field torsion measurements on solar trackers using fiber Bragg gratings are presented. 45 FBG sensors have been deployed in an operational solar energy plant to study the mechanical response of the structure to wind.
Open Access
L-band multiwavelength single-longitudinal mode fiber laser for sensing applications
(IEEE / OSA, 2012) Pérez Herrera, Rosa Ana; Ullán Nieto, Ángel; Leandro González, Daniel; Fernández Vallejo, Montserrat; Quintela, M. A.; Loayssa Lara, Alayn; López Higuera, José Miguel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a novel single-longitudinal-mode (SLM) four-wavelength laser configuration for sensing applications in the L-band is proposed and experimentally demonstrated. The sensor system presented here is based on ring resonators, and employs fiber Bragg gratings to select the operation wavelengths. The stable SLM operation is guaranteed when all the lasing channels present similar output powers. It is also experimentally demonstrated that when a SLMbehavior is achieved, lower output power fluctuations are obtained. Characterization of the lasing structure for temperature sensing is also shown.
Open Access
Optical fiber sensors for asphalt structures monitoring
(Optica Publishing Group, 2016) Bravo Acha, Mikel; Rota Rodrigo, Sergio; Leandro González, Daniel; Loayssa Lara, Alayn; Urricelqui Polvorinos, Javier; Bravo Acha, A.; Bravo Navas, M.; Mitxelena, J. R.; Martínez Mazo, J. J.; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A novel optical fiber installation method was explored for asphalt monitoring. Glassfiber polymer encapsulated SMF was installed in the intermediate and surface layers in order to study the strain sensitivity with a distributed strain interrogator.
Open Access
Ultra-long (290 km) remote interrogation sensor network based on a random distributed feedback fiber laser
(Optical Society of America, 2018) Miguel Soto, Verónica de; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, an interferometric sensor has been interrogated 290 km away from the monitoring station, reaching the longest distance in fiber optic sensing up to date. This has been attained by employing a double-pumped random distributed feedback fiber laser as the light source for a fiber optic low-coherence interferometry scheme. Additionally, the capability of the system to achieve coherence multiplexing for ultra-long range measurements (up to 270 km) has been proved, without presenting crosstalk between the sensors. The use of coherence multiplexing together with a random distributed feedback fiber laser addresses two of the main limitations of long-range sensing setups: their limited multiplexing capability and the need to reach the maximum monitoring distance.