Open Access
Concrete beam bending test monitorization using a high strain fiber optic sensor
(IEEE / OSA, 2012) Bravo Acha, Mikel; Sáenz, J.; Bravo Navas, M.; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work the development of an 'eight-shape' fiber optic sensor for high strain measurement is experimentally demonstrated. This strain sensor is interrogated using a commercial optical time domain reflectometer through a dual configuration that is able to measure backscattering and the transmission of an intensity pulse while reducing unwanted cladding-mode coupling effects. An 'in field' concrete beam bending test was also performed in order to compare the proposed low-cost intensity bending sensor with the mature fiber Bragg grating technology.
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
Power over fiber system for heterogeneous sensors multiplexing
(IEEE, 2024-06-12) Rodríguez Rodríguez, Armando; Vanegas Tenezaca, Evelyn Dayanara; Vento Álvarez, José Raúl; López-Amo Sáinz, Manuel; Bravo Acha, Mikel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Uniertsitate Publikoa
This paper presents a Power-over-Fiber based remote electronic and optical fiber sensors multiplexing scheme. The system architecture consists of a 50-km linear cavity Raman-fiber laser that is used for interrogation of FBG optical fiber sensors. Simultaneously, electronic sensors information is modulated in amplitude while the optical sensors' data are encoded in the spectral information. In order to bias the electronic sensors, the residual power of the Raman pump laser is collected in an energy harvesting unit. This electric power is used for biasing an ATTiny85 control unit and two electro-optical modulators. A proof-of-concept is presented where a couple of optical fiber-Bragg-gratings sensors collect strain information that is self-compensated in temperature according to the digital data achieved from the electronic sensors. A 9.6 kbit/s data rate was achieved using Mach-Zehnder amplitude modulators and a maximum 35 ksample/s was retrieved using a high-speed C-band spectrometer and performing spectral analysis via a software developed in Python. Authors
Open Access
Aluminum coated fiber optic sensor for enhancing flow rate measurement
(SPIE, 2023) Rodríguez Rodríguez, Armando; Urroz Unzueta, José Carlos; Diéguez Elizondo, Pedro; Bravo Acha, Mikel; López-Amo Sáinz, Manuel; López Rodríguez, José Javier; Ingeniería; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A water flow and velocity aluminum-coated Fiber Bragg Grating sensor system for open channels was designed, simulated and tested. The sensing head was designed, ruggedized and customized to measure velocities at different depths, in order to calculate the discharge in open channels. This paper shows, for the first time to our knowledge, the simulation of such kind of fiber sensors in open channels.
Open Access
One-year analysis of road condition using FBG arrays
(SPIE, 2023) Corera Orzanco, Íñigo; Pradas Martínez, Javier; Leandro González, Daniel; Bravo Acha, Mikel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA06-2022
In this work, it is presented an analysis of FBG arrays installed in a public road. The arrays were installed in a newly paved urban road and were monitored for more than one year. The study evidences the permanent deformation of the wearing course and the degradation of the reflected spectra of the sensors.