Open Access
Hybrid Raman‑erbium random fiber laser with a half open cavity assisted by artificially controlled backscattering fiber refectors
(Springer Nature, 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
A hybrid Raman-erbium random fber laser with a half-open cavity assisted by chirped artifcially controlled backscattering fber refectors is presented. A combination of a 2.4 km-long dispersion compensating fber with two highly erbium-doped fber pieces of 5 m length were used as gain media. A single random laser emission line centered at 1553.8 nm with an optical signal to noise ratio of 47 dB were obtained when pumped at 37.5 dBm. A full width at half maximum of 1 nm and a 100% confdence level output power instability as low as 0.08 dB were measured. The utilization of the new laser cavity as a temperature and strain sensor is also experimentally studied.
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
Virtual FBGs using saturable absorbers for sensing with fiber lasers
(MDPI, 2018) Rodríguez Cobo, Luis; Pérez Herrera, Rosa Ana; Quintela, M. A.; Ruiz Lombera, Rubén; 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
The spectral narrowing of Fiber Bragg Gratings (FBGs) introduced by unpumped Er-doped fiber (EDF) was analyzed for fiber lasers (FL). Owing to spatial hole burning (SHB), the spectral response of a virtual FBG can be employed for narrowing the band pass filter employed to determine the lasing wavelength of laser cavities. A common FL was mounted to analyze the spectral stability of the method, and a FL sensor for strain and temperature measurements was experimentally characterized to determine the stability of the narrowing effect achieved by the unpumped EDF, which acts as a virtual FBG. The results exhibited remarkably good narrowing effects of the spectral response of uniform FBGs.
Open Access
Tunable SESAM-based mode-locked soliton fiber laser in linear cavity by axial-strain applied to a FBG
(IEEE, 2017) Aporta, I.; Leandro González, Daniel; Quintela, M. A.; 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
A self-started stable tunable mode-locked (ML) soliton fiber laser in a linear cavity structure composed by commercial passive elements is presented in this paper. It is based on the combination of an Erbium doped fiber (EDF) as the active medium, and a saturated fiber Bragg grating (FBG) as a partial mirror of the cavity. The other side of the cavity consists of a semiconductor saturable absorber mirror (SESAM) acting also as the mode-locking device. The central wavelength of the FBG is selected by the application of axial strain giving rise to a tunable soliton over 8.6 nm on the C band with a variable spacing of 0.01 nm. The laser delivers 18.9 ps long pulses with a 0.14 nm bandwidth, an 8.2 MHz repetition rate, a pulse energy of 89 pJ and a peak power of 4.71 W.
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
A dual-wavelength fiber laser sensor with temperature and strain discrimination
(MDPI, 2022) Sánchez González, Arturo; Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Durán Escudero, Miguel; 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
This work presents a dual-wavelength C-band erbium-doped fiber laser assisted by an artificial backscatter reflector. This fiber-based reflector, inscribed by femtosecond laser direct writing, was fabricated into a single mode fiber with a length of 32 mm. The dual-wavelength laser obtained, centered at 1527.7 nm and 1530.81 nm, showed an optical signal-to-noise ratio over 46 dB when pumped at 150 mW. Another feature of this laser was that the power difference between the two channels was just 0.02 dB, regardless of the pump power, resulting in a dual emission laser with high equalization. On the other hand, an output power level and a central wavelength instability as low as 0.3 dB and 0.01 nm were measured, in this order for both channels. Moreover, the threshold pump power was 40 mW. Finally, the performance of this dual-wavelength fiber laser enhanced with a random reflector for sensing applications was studied, achieving the simultaneous measurement of strain and temperature with sensitivities around 1 pm/µε and 9.29 pm/°C, respectively.
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
Compact optical fiber lasers and optical fiber sensors assisted by femtosecond laser inscription of plane-by-plane FBGs
(Optica, 2020) Roldán Varona, Pablo; Pallarés Aldeiturriaga, D.; Rodríguez Cobo, Luis; Pérez Herrera, Rosa Ana; Bravo Acha, Mikel; 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
Development of a high temperature sensor based on optical fiber l aser generated from a cavity of reduced dimensions (43 mm) in Er-doped fiber. The mirror FBGs have been inscribed with femtosecond laser using the slit beam technique (Pl-b-Pl).
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
Microdrilled tapers to enhance optical fiber lasers for sensing
(Nature Research, 2021) 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; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, an experimental analysis of the performance of different types of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror is presented. These artificially-controlled backscattering fiber reflectors are used in short linear cavity fiber lasers. In particular, laser emission and sensor application features are analyzed when employing optical tapered fibers, micro-drilled optical fibers and 50 μm-waist or 100 μm-waist micro-drilled tapered fibers (MDTF). Single-wavelength laser with an output power level of about 8.2 dBm and an optical signal-to-noise ratio of 45 dB were measured when employing a 50 μm-waist micro-drilled tapered optical fiber. The achieved temperature sensitivities were similar to those of FBGs; however, the strain sensitivity improved more than one order of magnitude in comparison with FBG sensors, attaining slope sensitivities as good as 18.1 pm/με when using a 50 μm-waist MDTF as distributed reflector.