Open Access
One-year analysis of road condition using FBG arrays
(SPIE, 2023) Corera Orzanco, Íñigo; Pradas Martínez, Javier; Leandro González, Daniel; Bravo Acha, Mikel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA06-2022
In this work, it is presented an analysis of FBG arrays installed in a public road. The arrays were installed in a newly paved urban road and were monitored for more than one year. The study evidences the permanent deformation of the wearing course and the degradation of the reflected spectra of the sensors.
Open Access
Cavidad láser de fibra óptica multibanda basada en reflectores pseudoaleatorios cuasidistribuidos
(Sociedad Española de Óptica, 2021) Sánchez González, Arturo; 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
En este trabajo se presenta un análisis experimental de las prestaciones alcanzadas por una cavidad láser en línea asistida por un reflector de fibra con retrodispersión controlada artificialmente (RFRCA). Dicho reflector ha sido concebido para permitir oscilación en un único modo longitudinal (SLM) en bandas C y L, presentando inestabilidades en potencia de emisión inferiores a 0.1 dB y relaciones de señal óptica a ruido (OSNR) superiores a 44 dB.
Open Access
Internal modulation of a Random fiber laser
(Optical Society of America, 2013) Bravo Acha, Mikel; Fernández Vallejo, Montserrat; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A characterization of a modulated random mirror laser has been experimentally carried out. Unlike conventional internally modulated fiber lasers, no distortion of the modulating frequency or self-mode-locking effects were measured. The behavior of the laser using pulsed and analog modulation up to 12 GHz is shown.
Open Access
Simultaneous measurement of strain and temperature using a single emission line
(IEEE / OSA, 2015) Leandro González, Daniel; Ams, Martin; López-Amo Sáinz, Manuel; Sun, Tong; Grattan, Kenneth T. V.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we present and demonstrate a novel sensor system for simultaneous measurement of strain and temperature through a unique combination of a long period grating (LPG) and a fiber laser based on a fiber Bragg grating (FBG). In order to achieve this, a new erbium doped fiber laser (EDFL) structure is created, showing an optical signal-to-noise ratio (OSNR) of 55 dB and a peak power measured on the OSA between -5 and 0 dBm. The strain and the temperature information can be obtained by using a unique emission line through monitoring both the fiber laser wavelength shift and the change of the power level, both of which showing a clear linear behavior.
Open Access
Random DFB fiber laser for remote (200 km) sensor monitoring using hybrid WDM/TDM
(IEEE, 2016) Leandro González, Daniel; Miguel Soto, Verónica de; Pérez Herrera, Rosa Ana; Bravo Acha, Mikel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a random distributed feedback fiber laser is proposed as a multiplexing scheme for ultralong range measurements (up to 200 km). Optical fiber sensors are time and wavelength multiplexed overcoming one of the main limitations of long-range sensing setups, which is their limited multiplexing capability. The direct modulation of the laser's cavity allows the interrogation of sensors by measuring the reflected power for different wavelengths and distances. Fiber Bragg gratings placed at different fiber locations and wavelengths have been interrogated in two different sensor networks. In addition, in order to improve the performance of the system, some features have been analyzed.
Open Access
Low noise dual-wavelength erbium fiber laser in single-longitudinal-mode operation
(Springer, 2012) Rota Rodrigo, Sergio; Pérez Herrera, Rosa Ana; Fernández Vallejo, Montserrat; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A new stable dual-wavelength fiber-ring laser based on erbium-doped fiber amplification is reported. The laser is based on ring resonators and employs fiber Bragg gratings to select the operation wavelengths. The topology of the laser has a significant influence in its performance: allowing an independent control of the losses for both lasing wavelengths and achieving a low noise configuration. As a result, it is experimentally demonstrated that both emission lines work in single-longitudinal-mode operation and the topology offers a better stability and higher optical signalto-noise ratios than similar configurations.
Open Access
Compound lasing fiber optic ring resonators for sensor sensitivity enhancement
(IEEE / OSA, 2015) Rota Rodrigo, Sergio; González Herráez, Miguel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a new method for increasing simultaneously the sensitivity and interrogation stability of fiberoptic intensity sensors is presented. The configuration is based on a double-coupler ring resonator. On one side, the attenuation sensitivity of the sensor is enhanced by placing it inside a ring resonator. On the other side, the stability of the interrogation method is widely improved by creating an external lasing ring resonator with matched spectral response. The combination of the wavelength selective response of the ring resonator and optical amplification from Er-doped fiber amplifier is used to create different fiber lasers. The resulting lasers present an impressive sensitivity enhancement and a dynamic range increment up to 15 dB. Simultaneously, the instability of the system is reduced to ±0.05 dB. In comparison with systems based on tunable laser interrogation, our method is >100 times more stable and also simpler, as no wavelength tunable elements are required.
Open Access
Long-range hybrid network with point and distributed Brillouin sensors using Raman amplification
(Optical Society of America, 2010) Zornoza Indart, Ander; Pérez Herrera, Rosa Ana; Elosúa Aguado, César; Díaz Lucas, Silvia; Bariáin Aisa, Cándido; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We propose a novel concept for hybrid networks that combine point and distributed Brillouin sensors in a cost-effective architecture that also deploys remote distributed Raman amplification to extend the sensing range. A 46-km proof-of-concept network is experimentally demonstrated integrating point vibration sensors based on fiber Bragg gratings and tapers with distributed temperature sensing along the network bus. In this network the use of Raman amplification to compensate branching and fiber losses provides a temperature resolution of 0.7°C and 13 m. Moreover, it was possible to obtain good optical signal to noise ratio in the measurements from the four point vibration sensors that were remotely multiplexed in the network. These low-cost intensity sensors are able to measure vibrations in the 0.1 to 50 Hz frequency range, which are important in the monitoring of large infrastructures such as pipelines.
Open Access
Characterization of a hybrid Fabry-Pérot Cavity based on a four-bridge double-Y-shape-core microstructured fiber
(SPIE, 2014-06-02) Rodrigues Pinto, Ana Margarida; López Aldaba, Aitor; 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; Institute of Smart Cities - ISC
In this work, a hybrid Fabry-Perot interferometer based on a novel four-bridge microstructured fiber is presented and characterized. The characterization of this cavity is performed in the L-band using two different instruments: an optical spectrum analyzer and an optical backscatter reflectometer. The Fabry-Perot output signal presents linear variation with temperature changes (sensitivity 9.8-11.9 pm/ºC), variation with the polarization states of light and high stability.
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.