Open Access
Contribution to the development of Brillouin optical time-domain analysis sensors
(2016) Urricelqui Polvorinos, Javier; Loayssa Lara, Alayn; Sagüés García, Mikel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This thesis dissertation concentrates on solving some of the limitations described by proposing novel techniques. The first technique is based on using a phase-modulated probe wave with self-heteroyne detection and RF demodulation in BOTDA sensors. The self-heterodyne detection along with the RF demodulation allows to increase the SNR of vii the detected signal and to recover the amplitude of the Brillouin interaction as well as the phase-shift. The phase modulation allows to measure a phase-shift spectrum that obviously depends on the BFS measurement but also it is tolerant to changes of the pulse power and the attenuation of the fiber. This technique is interesting for dynamic BOTDA sensors, i.e. real-time monitoring sensors, in which attenuation of the optical fiber is a usual issue due to the losses caused by mechanical stress. Furthermore, as the technique is tolerant to changes of the peak power of the pulsed signal, it can tolerate non-local effects. This allows to increase the SNR by the increment of the probe power. Furthemore, this BOTDA sensor has been combined with a well-known technique, called differential pulse-width pair technique. It allows to enhance the spatial resolution without broadening the measured spectrum. In this case, the technique was applied to amplitude and phase-shift measurements. In addition to it, new approaches of this sensor based on the deployment of multiple pulsed signals with special features have been deployed to mitigate the effect of modulation instability and to reduce the measurement time in dynamic BOTDA sensors. A second technique proposed during this thesis dissertation is the BOTDA sensor using a probe wave whose optical frequency is modulated along the distance of the fiber. As mentioned before, if the BFS of the fiber is uniform, the effect induced by non-local effects is more detrimental. Consequently, if the probe wave changes along the fiber, the Brillouin interaction is not longer uniform and the probe power can be increased. Moreover, this technique also allows to reduce the noised added to the probe wave due to amplification of spontaneous Brillouin scattering components overcoming both limitations of the probe wave. Consequently, the proposed technique allows to considerably increase the precision of the sensor. In addition to it, the second technique is also useful to generate distributed Brillouin amplifiers (DBA). Combining the DBA with a standard BOTDA sensor, the DBA can transfer energy to the pulsed signal at the final kilometers of the fiber, i.e. the fiber section in which the pulsed signal has a low power due to the suffered attenuation. Therefore, the system allows to increase the detected SNR of the measurement. Finally, the thesis presents a study of the different noise sources that could affect to BOTDA sensors. Different noises sources such as double Rayleigh scattering generated by the probe wave or phase-to-intensity noise conversion in the SBS process are theoretically and experimentally analyzed. The study points out some guidelines of the importance of each noise for the different distance ranges in BOTDA sensors.
Open Access
Development and implementation of standardized interfaces for an Android based telemonitoring server
(2011) Urricelqui Polvorinos, Javier; Serrano Arriezu, Luis Javier; Gerbovics, Ferenc; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola Teknikoa; University of Applied Sciences Technikum Wien (Austria); Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
El tema de este proyecto fin de carrera es el desarrollo e implementación de interfaces estandarizadas para un servidor de telemonitorización basado en Android complementario al dispositivo HDH. El sistema de telemonitorización conocido como Health Data Hub (HDH) ha sido desarrollado por un grupo de estudiantes de Máster en la University of Applied Sciences Technikum Wien, obteniendo como resultado un dispositivo tipo muñequera capaz de medir datos médicos mediante sensores, recibir datos de parámetros vitales por parte de dispositivos para el cuidado de la salud, además del reenvío de datos como mensajes de alarma y diversas actualizaciones a distintos servidores mediante interfaces estandarizadas. Por lo que el principal objetivo de este proyecto es el desarrollo e implementación de interfaces estandarizadas para un servidor de telemonitorización basado en Android, capaz de gestionar los datos enviados por los dispositivos enmarcados en este proyecto según el estándar HL7 v2.6. El dispositivo HDH es capaz de medir parámetros vitales, generar actualizaciones automáticas y mensajes de alarma para enviarlos posteriormente al Android server mientras el paciente realiza su vida cotidiana. De esta manera, el usuario del Android server puede disponer de información relativa al usuario del HDH. El conjunto de dispositivos que se encuentran en el marco del proyecto HDH son el servidor HDH, el cliente HDH, el servidor Android y el dispositivo HDH. El servidor Android desarrollado durante este proyecto, consiste en una solución esencial de este entorno. El Android server está realizado sobre la plataforma Android, lo cual permite ofrecer nuevas funcionalidades y servicios que dotan de gran potencial al proyecto permitiendo llevar a cabo los objetivos propuestos. Además, Android se define como código abierto, lo cual permite al desarrollador una fácil integración a otros entornos y provee herramientas que permiten que el desarrollo de la aplicación sea más atractivo para el programador. Este proyecto ha sido desarrollado en colaboración con Amagoia Tellechea, estudiante de la Universidad Pública de Navarra y estudiante de intercambio Erasmus en la University of Applied Sciences Technikum Wien. Las tareas asignadas para el desarrollo de la aplicación Android server fueron proporcionadas a ambos estudiantes, por lo que se trabajó conjuntamente en el desarrollo de la aplicación desde sus inicios hasta las últimas soluciones adoptadas para su desarrollo.
Open Access
Dynamic BOTDA measurements based on Brillouin phase-shift and RF demodulation
(Optical Society of America, 2012) Urricelqui Polvorinos, Javier; Zornoza Indart, Ander; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate a novel dynamic BOTDA sensor based, for the first time to our knowledge, on the use of the Brillouin phase shift in addition to the conventional Brillouin gain. This provides the advantage of measurements that are largely immune to variations in fiber attenuation or changes in pump pulse power. Furthermore, the optical detection deployed leads to an enhanced precision or measurement time and to the broadening of the measurement range. Proof of concept experiments demonstrate 1.66 kHz measurement rate with 1 m resolution over a 160 m sensing fiber length. Moreover, a measurement range of 2560 µε with a precision of 20 µε is successfully proved.
Open Access
Brilloun optical time domain analysis sensor assisted by a Brillouin distributed amplifier
(SPIE, 2015) Urricelqui Polvorinos, Javier; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate the extension of the measurement range of Brillouin optical time-domain analysis (BOTDA) sensors using a distributed Brillouin amplifier (DBA). The technique is based on injecting a DBA pump wave in the fiber to generate an additional Brillouin interaction that amplifies the BOTDA pump pulses. Furthermore, the differential pulse-width pair method is used to counteract the detrimental effects of the DBA amplification on the temporal shape of the pulses. Experimental proof-of-concept results in a 50-km fiber link demonstrate full compensation of the fiber’s attenuation with no penalty on the signal-to-noise ratio of the detected probe wave.
Open Access
Polarization diversity scheme for BOTDA sensors based on a double orthogonal pump interaction
(IEEE, 2015) Urricelqui Polvorinos, Javier; López Fernandino, Felipe; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We introduce a Brillouin optical time domain analysis (BOTDA) sensor deploying a novel polarization diversity technique based on the use of two orthogonal pump pulses which simultaneously interact with a phase modulated probe wave. The orthogonallity of the two pump pulses guarantees that two complementary Brillouin interactions take place at each position of the fiber, so that polarization independent measurements are performed throughout the fiber even if no averaging is applied. This feature can be exploited in dynamic distributed BOTDA sensors to reduce the measurement time, as no extra averaging is required to compensate the polarization dependence of Brillouin interaction. Proof of concept experiments demonstrate the feasibility of the technique by employing a completely passive scheme to generate the orthogonal pump pulses. Furthermore, the technique is stable and easy to implement, making it a perfect candidate for practical sensor implementations.
Open Access
Fiber-optic brillouin distributed sensors: from dynamic to long-range measurements
(CRC Press, 2018) Loayssa Lara, Alayn; Urricelqui Polvorinos, Javier; Iribas Pardo, Haritz; Mompó Roselló, Juan José; Mariñelarena Ollacarizqueta, Jon; Estadística, Informática y Matemáticas; Ingeniería Eléctrica, Electrónica y de Comunicación; Estatistika, Informatika eta Matematika; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This chapter focuses on Brillouin optical time-domain analysis (BOTDA) sensors because they are the most successful Brillouin distributed sensors (BDS) type in terms of performance and practical applications. Distributed sensor featuring can be done in the time, coherence, or frequency domains, giving rise to the three main analysis BDS types: BOTDA, Brillouin optical correlation-domain analysis (BOCDA), and Brillouin optical frequency-domain analysis (BOFDA). The distance range of measurements performed using a BOTDA sensor is given by the length of sensing fiber that the system is able to measure with a specified performance in terms of measurement precision and time. The chapter reviews the fundamentals and the research directions in BDSs. The applications of the technology are multiple and in diverse fields¿for instance, in the oil and gas industry, where BDSs have been applied to measure temperature and strain along the umbilical cables used for subsea wells.
Open Access
Phase-shift based BOTDA measurements tolerant to non-local effects
(SPIE, 2013) Urricelqui Polvorinos, Javier; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate a BOTDA sensor based on the use of the Brillouin phase shift that performs measurements tolerant to non local effects. This technique raises opportunities to increase the distance covered by these sensors and the maximum optical power of the probe wave injected to the fiber. As a result, the system has the potential to increase the SNR achieved at the last meters of the fiber. Proof-of-concept experiments demonstrate unaltered measurements of the phase shift spectrum in a 20Km long fiber for large frequency-dependent distortions of the pump pulse.
Open Access
Brillouin optical time-domain analysis sensor with amplification of pump pulses and tolerant to non-local effects
(SPIE, 2016) Mompó Roselló, Juan José; Urricelqui Polvorinos, Javier; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensor with compensation for pump pulse attenuation and tolerance to non-local effects. The technique is based on operating the sensor in loss configuration so that energy is transferred from the probe wave to the pump pulse that becomes amplified as it counter-propagates with the probe wave. Furthermore, the optical frequency of the probe wave is modulated along the fiber so that the pump pulse experiences a flat gain spectrum that equally amplifies all the spectral components of the pulse, hence, preventing distortion. The method is experimentally demonstrated in a 100-km fiber link, obtaining a measurement uncertainty of 1 MHz at the worst-contrast position.
Open Access
Brillouin distributed sensing assisted by Brillouin amplification of pump pulses
(IEEE, 2014) Urricelqui Polvorinos, Javier; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate, for the first time to our knowledge, the extension of the measurement range of Brillouin distributed sensors (BDS) by using a distributed Brillouin amplifier (DBA) to compensate the attenuation of the sensor's pump pulses. The technique is based on injecting an extra DBA pump wave in the fiber to generate an additional Brillouin interaction to that used for sensing. Moreover, the bandwidth of the DBA is tailored to fit that of the pump pulses by deploying a wavelength modulation of the DBA pump that is synchronized to the pump. Experimental proof of concept results demonstrate a fivefold enhancement of the measurement range of a BDS, from 10.36 km to more than 50 km in this particular case. Moreover, it is found that the use of the DBA does not introduce any significant penalty in the detection signal to noise ratio, highlighting the potential of the technique to provide much larger sensing lengths.
Open Access
Latest research on long-range Brillouin distributed sensing
(SPIE, 2019) Loayssa Lara, Alayn; Urricelqui Polvorinos, Javier; Iribas Pardo, Haritz; Mariñelarena Ollacarizqueta, Jon; Mompó Roselló, Juan José; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua projecto 0011-1365-2017-000122
We review the latest developments in long-range Brillouin optical time-domain analysis sensors. The factors that impair the performance of these sensors, particularly in terms of their distance range, are discussed together with the latest methods to overcome them. We focus on our recent contributions based on the application of the probe dithering method, which is based on introducing a wavelength modulation to the probe wave. This technique is shown to effectively compensate nonlocal effects originated in the depletion of the pump pulse as well as of its pedestal. In addition, it can provide amplification to the pump wave with a slight modification of the setup. Furthermore, this method can be combined with pump pulse coding and a new technique for coding linearization that we have devised to further extend the sensing length into the hundreds of kilometers range.