Embargo
Optimization of optical spectroscopy classification algorithms for limited data scenarios in the food industry: tomato sauce samples case
(Elsevier, 2025-01-01) Gracia Moisés, Ander; Vitoria Pascual, Ignacio; Avedillo de la Casa, Amaia; Moreno Pérez, María; Imas González, José Javier; Ruiz Zamarreño, Carlos; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertistate Publikoa
This study addresses the problem of training deep learning models with limited datasets, a significant challenge in sectors like medical imaging and food quality analysis. To tackle this issue, generative adversarial networks (GANs) will be employed to augment the available data and improve model performance. An innovative approach is introduced here, integrating semi-supervised learning and generative modeling to maximize the use of small datasets in developing robust models. The method involves reversing the conventional distribution of training and testing data to focus on model evaluation and generalization from limited samples. Wasserstein GANs (WGANs) and Semi-Supervised GANs (SGANs), are utilized to supplement datasets with synthetic but realistic examples, enhancing the training process in scenarios of data scarcity. These techniques are applied in the context of visible reflectance spectroscopy to analyze tomato sauces, demonstrating the method's effectiveness in non-invasively assessing key quality parameters such as oil content, °Brix, and pH. The results show significant improvements in model performance metrics: for %Oil content, overall accuracy increased from 0.47 to 0.66; for °Bx, it rose from 0.65 to 0.71; and for pH measurement, accuracy improved from 0.43 to 0.62. These outcomes highlight the model's improved capability to generalize and maintain accuracy with limited data.
Open Access
Experimental demonstration of the impact of the fringe shape in sub-lambda/2 sensing with optical feedback interferometry
(Optica Publishing Group, 2020-12-22) Knudsen, Einar; Perchoux, Julien; Mazoyer, Thierry; Imas González, José Javier; Veng, Mengkoung; Jayat, Francis; Tronche, Clément; Bosch, Thierry; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
It is established in the optical feedback interferometry (OFI) theory that the shape of the interferometric fringe has an impact on the detector's response to very small displacement measurements. In this paper, we validate¿for the first time, to the best of our knowledge, based on experimental results¿this statement by comparing experiments to an established model implementation. Through these experiments, we show that the amplitude of the signals induced by sub-lambda/2 optical path variations is linearly dependent on the slope of the underlying fringe. Thus, careful control of the phase allows us to maximize the detection amplitude of very small displacements by positioning the phase where the fringe slope is the steepest. These results are directly applicable to established OFI applications that measure sub-lambda/2 optical path variations, such as OFI vibrometers or acoustic imaging though the acousto-optic effect.
Open Access
Design and fabrication of novel optical fiber architectures for sensing applications
(2022) Imas González, José Javier; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Los sensores de fibra óptica han experimentado un importante progreso en los últimos años con el empleo de estructuras basadas en redes de Bragg, interferómetros o resonancias electromagnéticas, entre otras y el desarrollo de la nanotecnología, que ha permitido la deposición de recubrimientos a nivel micro y nanométrico sobre la fibra. Estos avances han posibilitado la fabricación de sensores de fibra óptica para medir variables físicas, parámetros químicos o aplicaciones de biosensado. Esta tesis contribuye al análisis y optimización, tanto teórica como experimental, de diferentes configuraciones y estructuras en fibra óptica, aplicadas al desarrollo de sensores. En esta tesis se estudian varias estructuras, incluidas las Lossy Mode Resonances (LMRs) y redes en fibra óptica: FBGs (redes de Bragg en fibra), LPGs (redes de período largo en fibra) y TFBGs (redes de Bragg inclinadas en fibra). Las principales líneas de investigación que se presentan en esta tesis son la fabricación de dispositivos multisensores basados en LMRs y la mejora del fenómeno de la mode transition en redes de fibra óptica: LPGs en fibras con doble cladding y TFBGs. El elemento común entre ambas líneas de investigación es el empleo de películas delgadas de materiales de alto índice de refracción: óxido de estaño (SnO2), óxido de indio y estaño (ITO) y dióxido de titanio (TiO2). Los resultados mostrados en esta tesis revelan el potencial de combinar varias estructuras y/o fenómenos en fibras ópticas para mejorar el desempeño de los sensores de fibra óptica.
Open Access
A systemic model for lossy mode resonances (LMRs)
(Elsevier, 2024-11-07) Imas González, José Javier; Del Villar, Ignacio; Halir, Robert; Wangüemert-Pérez, J. Gonzalo; Ortega-Moñux, Alejandro; Matías Maestro, Ignacio; Molina-Fernández, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Lossy mode resonances (LMRs) have been widely employed for the development of sensors in the last years. However, the theoretical frameworks for LMRs are scarce and difficult to systematize, hampering the development of this technology. In this work, we propose a new systemic model for assessing LMRs in arbitrary waveguide configurations, based solely on modal analysis of the unperturbed waveguide and the waveguide with a thin film optimized for LMR generation. The model is first developed for a generic waveguide, and leveraged to design, for the first time, LMRs in a silicon nitride photonic wire waveguide. It is furthermore demonstrated that the model only requires a few modes to reliably describe LMRs in D-shaped fibers, reducing the computational cost of simulating them. Therefore, the suggested model is valid for both high and low contrast waveguides, and it is considered it provides new insights about LMRs, which will help in the design of new LMR-based devices and its extension to novel platforms.
Open Access
Proyectos electrónicos con microcontrolador PIC16F877A
(2017) Imas González, José Javier; Ruiz Zamarreño, Carlos; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola Teknikoa
El presente trabajo fin de grado comprende el desarrollo e implementación de 3 proyectos electrónicos basados en el microcontrolador PIC16F877A. Cada proyecto ha constado de las siguientes etapas: fase de pruebas y programación, diseño del circuito electrónico, diseño y fabricación del circuito impreso (PCB), montaje de los componentes sobre el circuito impreso, puesta en funcionamiento y diseño de una carcasa mediante software 3D. El primer proyecto, en el que la programación cobra mayor importancia, es un relojdespertador basado en la comunicación I2C entre el microcontrolador y el RTC (Real Time Clock) DS3231 y que utiliza una pantalla LCD 2x16. Los dos proyectos restantes poseen un carácter más práctico. El segundo proyecto es un juguete consistente en dos servomotores y un diodo láser controlados de forma autónoma mediante un joystick. El último proyecto es un cubo de LEDs RGB (Red, Green, Blue) 3x3x3 en el que la iluminación de cada uno de los 81 LEDs se controla de forma independiente
Open Access
Optical biosensors: a quick overview
(2021) Imas González, José Javier; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This work aims to provide a brief overview of the latest trends in the domain of optical biosensors.
Open Access
Air bubble detection in water flow by means of ai-assisted infrared reflection system
(IEEE, 2024-06-26) Gracia Moisés, Ander; Vitoria Pascual, Ignacio; Imas González, José Javier; Ruiz Zamarreño, Carlos; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
This letter introduces an innovative, cost-effective solution for detecting air bubbles in water flow systems using an AI-assisted infrared reflection system. In industries, such as chemical, mechanical, oil, and nuclear, the presence of air bubbles in fluids can compromise both product quality and process efficiency. Our research develops a system that combines infrared optical sensors with machine learning algorithms to detect and quantify bubble presence effectively. The system’s design utilizes infrared emitters and photodetectors arranged around a pipe to capture detailed data on bubble characteristics, which is then analyzed using a support vector machine (SVM) model to predict bubble concentrations. Experimental results demonstrate the system’s ability to accurately identify different levels of bubble presence, offering significant improvements over existing methods. Key performance metrics include a mean squared error of 0.0694, a root mean squared error of 0.2634, and a coefficient of determination of 0.9765, indicating high accuracy and reliability. This approach not only enhances operational reliability and safety but also provides a scalable solution adaptable to various industrial settings.
Open Access
Beyond near-infrared lossy mode resonances with fluoride glass optical fiber
(Optica, 2021) Vitoria Pascual, Ignacio; Ruiz Zamarreño, Carlos; Ozcariz Celaya, Aritz; Imas González, José Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The objective of this Letter consists of the exploration of the lossy mode resonance (LMR) phenomenon beyond the nearinfrared region and specifically in the short wave infrared region (SWIR) and medium wave infrared region (MWIR). The experimental and theoretical results show for the first time, to the best of our knowledge, not only LMRs in these regions, but also the utilization of fluoride glass optical fiber associated with this phenomenon. The fabricated devices consist of a nanometric thin-film of titanium dioxide used as LMR generating material, which probed extraordinary sensitivities to external refractive index (RI) variations. RI sensitivity was studied in the SWIR and MWIR under different conditions, such as the LMR wavelength range or the order of resonance, showing a tremendous potential for the detection of minute concentrations of gaseous or biological compounds in different media.
Open Access
Surface exciton polariton resonances (SEPR)-based sensors
(Elsevier, 2023) Vitoria Pascual, Ignacio; Ruiz Zamarreño, Carlos; Ozcariz Celaya, Aritz; Imas González, José Javier; Del Villar, Ignacio; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
A new type of resonance in the development of sensors using long-range surface exciton polariton (LRSEP) phenomena has been coined: surface exciton plasmon resonance (SEPR). The resonance was obtained in the reflected spectrum of a Kretschmann-Raether setup with a two-coupled-interface structure composed of 412 nm magnesium fluoride and 50 nm chromium thin films. The roles of different parameters such as thicknesses of the films and the incidence angles have been simulated. Some preliminary experimental results show a promising performance with a shift of the resonance central wavelength with changes in the incidence angle of -136.52 nm/° and a sensitivity of 23,221 nm/refractive index unit.
Open Access
Mode transition during deposition of nanoscale ITO coatings on tilted fiber Bragg gratings
(Optica Publishing Group, 2022) Imas González, José Javier; Albert, Jacques; Del Villar, Ignacio; Ozcariz Celaya, Aritz; Ruiz Zamarreño, Carlos; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The mode transition phenomenon is experimentally demonstrated in tilted fiber Bragg gratings (TFBG) through the deposition of an indium tin oxide (ITO) thin film employing a DC sputtering machine.