Open Access
Experimental optimization in terms of power stability and output power of highly Er-doped fiber lasers with single and hybrid cavities
(Taylor & Francis, 2010) Pérez Herrera, Rosa Ana; Chen, Shuying; Zhao, Weizhong; Sun, Tong; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this article, the output power stability of several different highly erbiumdoped fiber ring lasers, as a function of the laser parameters, is experimentally investigated. The study is focused on the optimization of several key parameters (erbium-doped fiber length, pump power, and different laser configurations) without changing the basic scheme. The results obtained show that the laser configuration plays an important role in achieving stable multi-wavelength lasing at room temperature in the erbium-doped fiber ring lasers. For an optimized configuration, these power fluctuations are lower than 0.08 dB, showing a notable improvement compared with previously presented work where the output power variations were about 0.2 dB. These lasers have the advantage of a simple all-fiber configuration, low cost, high stability, and operability at room temperature.
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
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
Multiplexing optical fiber Fabry-Perot interferometers based on air-microcavities
(SPIE, 2019) Pérez Herrera, Rosa Ana; Novais, Susana; Bravo Acha, Mikel; Leandro González, Daniel; Silva, Susana; Frazão, Orlando; 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 demonstrate the multiplexing capability of new optical fiber Fabry-Perot interferometers based on airmicrocavities using a commercial FBG interrogator. Three optimized air-microcavity interferometer sensors have been multiplexed in a single network and have been monitored using the commercial FBGs interrogator in combination with FFT calculations. Results show a sensitivity of 2.18 π rad/mε and a crosstalk-free operation.
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
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
Gamma radiation-induced effects over an optical fiber laser: towards new sensing applications
(MDPI, 2020) Pérez Herrera, Rosa Ana; Stancalie, Andrei; Cabezudo Sánchez-Valverde, Pablo Miguel; Sporea, Dan; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In the present work, the effect of gamma radiation on the performance of different types of erbium-doped fibers (EDFs) when they are used in a fiber ring cavity (FRC) configuration is studied. Several pieces of commercial EDF are gamma-ray irradiated with different doses to evaluate the output power variations over time. The influence of different doses, from 150 Gy to 1000 Gy, over the output power level measurement and their amplified spontaneous emission (ASE) are experimentally evaluated both in the C and L bands. By using an FRC configuration we can detect the presence of gamma radiation. We can also estimate the irradiation doses applied to EDFs by measuring the slope of the short-term emission power.
Open Access
Simultaneous measurement of humidity and vibration based on a nanowire sensor system using Fast Fourier Transform technique
(IEEE, 2016) Rota Rodrigo, Sergio; López Aldaba, Aitor; Pérez Herrera, Rosa Ana; López Bautista, María del Carmen; Esteban, Óscar; 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 ...
Open Access
Optical fiber bus protection network to multiplex sensors: experimental validation of self-diagnosis
(IEEE, 2012) Pérez Herrera, Rosa Ana; Urquhart, Paul; Schlüter, Marcel; Díaz Lucas, Silvia; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The experimental demonstration of a resilient wavelength division multiplexed (WDM) fiber bus network to interconnect sensors is reported. The network recovers operation after failures and it performs 'self-diagnosis', the identification of the failed constituent(s) from the patterns of surviving end-toend connections at its operating wavelengths. We provide clear evidence for the channel arrivals predicted by theory. In doing so, we explore the potential for spurious signals caused by reflections from broken fiber ends. Appropriate precautionary measures, especially the imposition of electronic thresholds at the receivers, can greatly reduce the scope for false diagnoses. Software to predict the failure site within the network from the arriving channels at the receivers is also reported. We describe how to coordinate self-diagnosis with protection switching so as to reduce the momentary service interruption.
Open Access
Random fiber lasers: application to fiber optic sensors networks
(IEEE, 2017) López-Amo Sáinz, Manuel; Leandro González, Daniel; Miguel Soto, Verónica de; Bravo Acha, Mikel; Fernández Vallejo, Montserrat; Pérez Herrera, Rosa Ana; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
Recently, random mirrors have been proposed as a method to create fiber laser cavities. This kind of cavity is based on cooperative Rayleigh scattering, which is generated along a fiber due to the material inhomogeneities presented in that fiber. In this work, basics of Random fiber lasers and different demonstrated lasing sensors systems for interrogating arrays of optical fiber sensors are shown. These systems use different kinds of amplification and cavities schemes and can interrogate optical fiber sensors located up to 225 km away.