Open Access
Simultaneous measurement of humidity and vibration based on a microwire sensor system using Fast Fourier Transform technique
(IEEE, 2016) Rota Rodrigo, Sergio; López Aldaba, Aitor; Pérez Herrera, Rosa Ana; López Bautista, María del Carmen; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This paper presents a new sensor system for vibration and relative humidity measurements based on its interaction with the evanescent field of a microwire. The interrogation of the sensing head is carried out by monitoring the fast Fourier transform (FFT) phase of one of the FFT peaks of the microwire transmission signal. This technique is not dependent of the signal amplitude and also eludes the requisite of tracking the wavelength evolution in the spectrum, which can be a handicap when there are multiple interference frequency components with different sensitivities. The point sensor is able to measure a wide humidity range (20%-70% relative humidity) with a maximum sensitivity reached of 0.14πrad/% relative humidity. This microwire sensor is also operated within a frequency range from 320 to 1300 Hz with a sensitivity of around 0.0051 nm -1 /Hz. Finally, due to the system uses an optical interrogator as unique active element, the system presents a cost-effective feature.
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
Simultaneous measurement of strain and temperature based on clover microstructured fiber loop mirror
(Elsevier, 2015) Pérez Herrera, Rosa Ana; André, R. M.; Silva, S. F.; Becker, M.; Schuster, K.; Kobelke, J.; López-Amo Sáinz, Manuel; Santos, José Luís; Frazão, Orlando; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, two all-fiber loop mirrors using a clover microstructured fiber for the simultaneous measurement of temperature and strain are presented. The sensing heads are formed by a short piece of clover microstructured fiber with 35 mm and 89 mm length respectively. The geometry of the fiber allowed observing different interferences created by the microstructured fiber core section. Different sensitivities to temperature and strain were obtained and, using a matrix method, it is possible to discriminate both physical parameters. Resolutions of ±2ºC and ±11 μ for the first structure and ±2.3ºC and ±18 μ for the second one, for temperature and strain, respectively, were attained.
Open Access
Diseño y caracterización de reflectores incoherentes de retrodispersión de fibra microperforada para láseres random de fibra óptica
(SEDOPTICA, 2021) Galarza Galarza, Marko; Sañudo-Lasagabaster Ibáñez, Silvia; Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Rodríguez Cobo, Luis; López Higuera, José Miguel; 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, PJUPNA 1928
Los láseres random de fibra óptica presentan una serie de características que los hacen idóneos para una gran variedad de aplicaciones industriales. La elevada longitud de fibra necesaria en la cavidad debido a sus bajos índices de dispersión Rayleigh, se reduce utilizando fibras de baja área efectiva (compensadoras de dispersión), o generando artificialmente elementos muy dispersivos. En este trabajo presentamos el diseño de reflectores aleatorios de tan solo varios milímetros, generados mediante microperforación del núcleo con un láser de femtosegundo y su utilización en la cavidad de una estructura láser.
Open Access
Frequency modulated continuous wave system for optical fiber intensity sensors with optical amplification
(IEEE, 2009) Pérez Herrera, Rosa Ana; Frazão, Orlando; Santos, José Luís; Araújo, Francisco Moita; Ferreira, Luis Alberto; Baptista, José Manuel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We report on the use of erbium doped fiber (EDF) amplification to enhance a frequency modulated continuous wave (FMCW) technique for referencing optical intensity sensors located between two Bragg grating structures. The experiment combines the concept of FMCW with the spectrally selective mirror properties of Bragg gratings to interrogate with referencing properties intensity based sensors. The interrogation system without amplification yields a sensor resolution of around 0.078 dB. When the EDF amplifier is introduced into the experimental set up, the sensor sensitivity does not change, but the signal-to-noise ratio is improved, resulting into an enhanced resolution of 0.025 dB. We also obtain a remote sensing operation at a location of 50 km, showing the feasibility of this configuration to be used as a remote sensing application.
Open Access
Stabilization of dual-wavelength erbium doped ring fiber lasers by single-mode operation
(IEEE, 2010) Quintela, M. A.; Pérez Herrera, Rosa Ana; Canales, Irene; Fernández Vallejo, Montserrat; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a novel single-longitudinal-mode (SLM) dual-wavelength laser configuration is proposed and demonstrated. This laser is based on ring resonators, and employs fiber Bragg gratings to select the operation wavelengths. It includes a short piece of highly doped Er-fiber that acts as the active medium. The stable SLM operation is guaranteed when the two lasing channels present similar output powers. This behavior is shown for different pump powers.
Open Access
C and L band fiber lasers enhanced by ultrafast laser inscribed artificial backscatter reflectors
(Optica, 2022) Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Sánchez González, Arturo; Rodríguez Cobo, Luis; López Higuera, José Miguel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This letter presents an experimental comparison between two linear-cavity erbiumdoped fiber lasers (EDFL) assisted by two different artificial backscatter fiber-based reflectors. Both reflectors were inscribed by femtosecond laser direct writing, one of them within a single-mode fiber (SMF) and the other one within a multi-mode fiber (MMF). Although the erbium-doped fiber amplifier (EDFA) used in both structures was the same and both reflectors were manufactured under the same parameters, the reflection spectrum of each was clearly different due to their different physical properties. The first linear-cavity EDFL, consisting of an SMF-based reflector with 9µm core and 125µm cladding, resulted in a single laser emission line located in the C-band and centered at 1564.4 nm, exhibiting an optical signal-to-noise ratio (OSNR) of 52dB when pumped at 100mW. On the other hand, a single laser emission line with a similar OSNR but in L-band (centered at 1574.5nm) was obtained when using an MMF-based reflector with 50µm core and 125µm cladding.
Open Access
Micro-displacement sensor based on hollow core fiber interferometers
(Optica, 2022) Sánchez González, Arturo; Rodríguez Rodríguez, Armando; Dauliat, Romain; Jamier, Raphael; Roy, Philippe; Pérez Herrera, Rosa Ana; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
An interferometric sensor based on hollow core fibers for the measurement of micro-displacement has been designed. Its characterization has resulted in a linear response, suggesting its application in pressure sensors.
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
Láser random de fibra óptica asistido por reflectores de fibra con retrodispersión controlada artificialmente
(SEDOPTICA, 2021) Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Galarza Galarza, Marko; Sañudo-Lasagabaster Ibáñez, Silvia; Rodríguez Cobo, Luis; López Higuera, José Miguel; 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, PJUPNA1928
Este trabajo presenta un láser de fibra tipo random (LFR) en cavidad semi-abierta, mediante amplificación híbrida Raman-Erbio y asistida por reflectores de fibra con retrodispersión controlada artificialmente (RFRCA). Como medio activo se ha empleado una combinación de 2,4 km de fibra compensadora de dispersión con dos tramos de fibra altamente dopada con erbio de 5 m cada uno. Se ha obtenido una única línea de emisión láser centrada a en 1553.8 nm y con una relación señal a ruido óptica de 47 dB cuando en la estructura se inyectaba una potencia de bombeo de 37.5 dBm. Además, se ha medido la estabilidad en términos de potencia de salida de este láser durante 3 horas, obteniendo una inestabilidad tan baja como 0,08 dB con un nivel de confianza del 100%.