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
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
Study of in-line capillary fiber sensor for uniaxial transverse deformation
(IEEE, 2024-08-06) Sánchez González, Arturo; Leandro González, Daniel; Dauliat, Romain; Jamier, Raphael; Roy, Philippe; Pérez Herrera, Rosa Ana; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA06-2022
This research explores the impact of cyclic uniaxial transverse deformation on an in-line hollow-core fiber etalon. The structure consists of a 6 mm long section of capillary fiber spliced between two standard single-mode fibers. The optical response of the structure is theoretically analyzed in spectral and transformed domains, evidencing Fabry-Perot and antiresonant interferometric mechanisms. A validation of the theoretical behavior is carried out both through simulation and experimentation. The performance of the structure for uniaxial transverse deformation is subsequently evaluated by tracking the phase of the main component in the transformed domain. The relevance of measuring in the time domain is discussed, demonstrating improved accuracy over wavelength shift and inverse spatial domain methods. Several sensors with different internal diameters underwent cycles of transverse deformation, revealing robust linear trends in every case. On average, the structure demonstrated elastic behavior under deformations up to 42 μm, with a mean sensitivity of 0.174 rad/μm, and mechanical breakage taking place at 58 μm. The results confirmed the suitability of the sensor to withstand uniaxial micro-displacements or pressures, with smaller inner diameter capillary fibers showing the best performance.
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
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
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
Open Access
Multicore fiber sensors for strain measurement towards traffic monitoring
(SPIE, 2023) Sánchez González, Arturo; Pradas Martínez, Javier; Corera Orzanco, Íñigo; Bravo Acha, Mikel; Leandro González, Daniel; 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; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA06-2022
In this work, two new interferometric sensors based on multicore optical fibers for the measurement of strain with the ultimate goal of traffic monitoring are presented. The operating principle of each sensor relied on the monitoring of the phase shift difference accumulated between the supermodes of the structure of the multicore segment in a full round trip. The strain characterization for both sensors resulted in a linear response, with sensitivities of -4.073·10-3 rad/με and - 4.389·10-3 rad/με for the aligned and V-shaped cases respectively, and one-hour instabilities below 4.6·10-3 rad with a 95% confidence level. These results suggest its feasibility in applications requiring high sensitivities over very wide strain ranges, such as heavy-vehicle traffic monitoring. To corroborate the hypothesis, both sensors were integrated into the pavement and their response to the traffic was analyzed.
Open Access
Stable L-band fiber laser sensor using a backscattering-based multimode fiber reflector
(Optica Publishing Group, 2022) Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Sánchez González, Arturo; Durán Lázaro, María; 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 new and highly stable L-band fiber laser for sensing is demonstrated. An emission line at 1575.47 nm, was achieved using a special reflector. Good strain sensitivity, optical signal to noise ratio and output power stability were measured.
Open Access
Quasi-distributed 3-cm vibration and strain monitoring using OFDR and in-line interferometers
(IEEE, 2024-06-21) Sánchez González, Arturo; Leandro González, Daniel; Shi, Muyu; Zhu, Mengshi; Murayama, Hideaki; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This study presents a new quasi-distributed vibration sensing approach with a 3-cm spatial resolution, capable of performing multiparameter measurements. In-line interferometers are employed simultaneously as strain point sensors and reflectors for vibration monitoring due to the Doppler effect. The interferometers consist of capillary fiber segments spliced between single-mode fibers, forming a sensing etalon. A study of the characteristics required for the fiber array fabrication is carried out. A 60 cm array comprising 20 sensing sections is used for the proof-of-concept of the technique for strain and vibration sensing. An analysis of the behavior for static strain and vibrations is performed, both individually and simultaneously, using a free-end cantilever experiment.
Open Access
High performance fiber laser resonator for dual band (C and L) sensing
(IEEE, 2022) 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
This work presents an experimental analysis and comparison of the performance of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror both in C- and L-band. Single-wavelength emission has been obtained in either band when using these artificially controlled backscattering fiber reflectors in a ring-cavity fiber laser. Single-longitudinal mode operation with an optical signal to noise ratio (OSNR) of 47 dB and an output power instability as low as 0.04 dB have been measured when employing a C-band optical amplifier. When replaced by an L-band optical amplifier, a single-longitudinal mode behavior has also been obtained, showing an OSNR of 44 dB and an output power instability of 0.09 dB. Regarding their performance as fiber-laser sensing systems, very similar temperature and strain sensitivities have been obtained in both bands, comparable to fiber Bragg grating sensors in the case of temperature and one order of magnitude higher in the case of strain variations.