Open Access
Single-longitudinal mode laser structure based on a very narrow filtering technique
(Optical Society of America, 2013) Rodríguez Cobo, Luis; Quintela, M. A.; Rota Rodrigo, Sergio; López-Amo Sáinz, Manuel; López Higuera, José Miguel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A narrow filtering technique based on the spectral overlapping of two uniform FBGs and applied to obtain a Single Longitudinal Mode (SLM) laser is proposed and demonstrated in this work. The two FBGs are spectrally detuned to reduce their coincident reflection response narrowing the equivalent filter bandwidth. A proof-of-concept linear laser has been built and tested exhibiting SLM operation even with temperature and strain variations.
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%.
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
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
Optical fiber lasers assisted by microdrilled optical fiber tapers
(Optical Society of America, 2019) Pérez Herrera, Rosa Ana; Pallarés Aldeiturriaga, D.; Júdez Colorado, Aitor; Rodríguez Cobo, Luis; López-Amo Sáinz, Manuel; López Higuera, José Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this Letter, we present an analysis of the backscattering generated in a microdrilled tapered fiber within a short-linear-cavity fiber laser. We propose and experimentally demonstrate a fiber cavity laser based on a tapered optical fiber segment that generates artificially controlled backscattering. The 50-mu m-waist taper was fabricated from a standard single-mode fiber, and the taper was subsequently microdrilled using a femtosecond laser micromachining system. The laser generation properties conferred by the microdrilled optical fiber taper were experimentally investigated. A single-wavelength laser emission at 1562 nm with an output power of 10 dBm and an optical signal-to-noise ratio greater than 45 dB is demonstrated.
Open Access
Influence of saturable absorbers on fiber ring laser sensors
(SPIE, 2017) Rodríguez Cobo, Luis; Quintela, M. A.; Ruiz Lombera, Rubén; Pérez Herrera, Rosa Ana; López-Amo Sáinz, Manuel; López Higuera, José Miguel; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this work, a fiber ring laser sensor has been employed to analyze the influence of passive Er-doped fiber acting as saturable absorber. Lasing modes of fiber ring lasers can be reduced by properly locating a saturable absorber that narrows the spectral width of the FBG that selects the lasing wavelength. Employing commercial Er-doped fiber, different configurations have been evaluated, reaching the SLM regime on a ring cavity of several meters. Thus, the achieved strain response of the whole sensor behaves at its mirror FBG, exhibiting linear response to strain.
Open Access
Micro-drilled optical fiber for enhanced laser strain sensors
(SPIE, 2019) Pérez Herrera, Rosa Ana; Bravo Acha, Mikel; Roldán Varona, Pablo; Leandro González, Daniel; 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
In this work, we present an experimental measurement of temperature and strain sensitivities of a micro-drilled optical fiber (MDOF). The MDOF consisted of a quasi-randomly distributed reflector along a single mode fiber (SMF). A fiber cavity laser based on MDOF was experimentally studied, attaining a single-wavelength laser emission centered at 1568.6nm. The output power level obtained from this single-laser oscillation when pumped at 140mW was around - 9.6dBm, and an optical signal to noise ratio (OSNR) of around 45dB was measured. Although temperature sensitivities of fiber Bragg gratings used as sensors are similar to our MDOF, strain sensitivity is enhanced around one order of magnitude when the MDOF was used.
Open Access
Application of remote power-by-light switching in a simplified BOTDA sensor network
(MDPI, 2013) Bravo Acha, Mikel; Zornoza Indart, Ander; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; López Higuera, José Miguel; Ullán Nieto, Ángel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We propose and demonstrate the use of spatial multiplexing as a means to reduce the costs of distributed sensing networks. We propose a new scheme in which remote power-by-light switching is deployed to scan multiple branches of a distributed sensing network based on Brillouin Optical Time Domain Analysis (BOTDA) sensors. A proof-of-concept system is assembled with two 5-km sensor fiber branches that are alternatively monitored using a fast remotely controlled and optically powered optical switch. The multiplexed distributed sensor fibers were located 10 km away from the interrogation unit and a Raman pump is used to remotely power the switch. Furthermore, the deployed BOTDA unit uses an alternative configuration that can lead to simplified setups.
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
Wavelength-switchable L-band fiber laser assisted by random reflectors
(EDP Open, 2023) 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
A wavelength-switchable L-band erbium-doped fiber laser (EDFL) assisted by an artificially controlled backscattering (ACB) fiber reflector is here presented. This random reflector was inscribed by femtosecond (fs) laser direct writing on the axial axis of a multimode fiber with 50 lm core and 125 lm cladding with a length of 17 mm. This microstructure was placed inside a surgical syringe to be positioned in the center of a high-precision rotation mount to accurately control its angle of rotation. Only by rotating this mount, three different output spectra were obtained: a single wavelength lasing centered at 1574.75 nm, a dual wavelength lasing centered at 1574.75 nm and 1575.75 nm, and a single wavelength lasing centered at 1575.5 nm. All of them showed an optical signal-to-noise ratio (OSNR) of around 60 dB when pumped at 300 mW