Numerical implementation of generalized Coddington equations for ophthalmic lens design

Postprint (author's final draft

Polarization calibration assessment for a broadband imaging polarimeter based on a division of aperture architecture

This article intends to provide all the experimental insights and analyze the best polarimetric calibration method for a division of aperture polarimetric imager considering the different implications it has on the experimental set-up and its performance. Polarimetric cameras require careful calibration for the correct measurement of polarization information. The calibration methods are introduced, intermediate results are presented, and the ability of the set-up to estimate Stokes vectors and Mueller matrices of the samples in passive and active imaging modes is evaluated. Polarization information recovery achieves accuracy errors below the 10% for all polarization modes when the Data Reduction Matrix or the Eigenvalue Calibration Method are used. Such performance, however, degrades significantly when using the Polarizer Calibration Method. To the best of our knowledge, this is the first time such a detailed comparison of calibration methods is presented in the literature, and it is also the first time the Polarizer Calibration Method is applied to a division of aperture polarimeter.Ministerio de Ciencia e Innovación (PDC2021-121038-I00, PID2020-119484RB-I00); Agència de Gestió d’Ajuts Universitaris i de Recerca (2020FI_B2 00068); European Social Fund; Universitat Politècnica de Catalunya; Banco Santander.Peer ReviewedPostprint (published version

An overview of lidar imaging systems for autonomous vehicles

Lidar imaging systems are one of the hottest topics in the optronics industry. The need to sense the surroundings of every autonomous vehicle has pushed forward a race dedicated to deciding the final solution to be implemented. However, the diversity of state-of-the-art approaches to the solution brings a large uncertainty on the decision of the dominant final solution. Furthermore, the performance data of each approach often arise from different manufacturers and developers, which usually have some interest in the dispute. Within this paper, we intend to overcome the situation by providing an introductory, neutral overview of the technology linked to lidar imaging systems for autonomous vehicles, and its current state of development. We start with the main single-point measurement principles utilized, which then are combined with different imaging strategies, also described in the paper. An overview of the features of the light sources and photodetectors specific to lidar imaging systems most frequently used in practice is also presented. Finally, a brief section on pending issues for lidar development in autonomous vehicles has been included, in order to present some of the problems which still need to be solved before implementation may be considered as final. The reader is provided with a detailed bibliography containing both relevant books and state-of-the-art papers for further progress in the subject.Peer ReviewedPostprint (published version

Frequency-Modulated Optical Feedback Interferometry for Nanometric Scale Vibrometry

We demonstrate a novel method that makes an efficient use of laser nonlinear dynamics when subject to optical self-injection for subwavelength displacement sensing purposes. The proposed methodology combines two different phenomena taking place inside the laser cavity: optical self-injection, which results in optical feedback interference, and laser continuous wave frequency modulation, giving rise to a wavelength sweeping effect in the laser's emission. We present a combination of these phenomena to measure vibration amplitudes below lambda/2 with the resolutions of a few nanometers, bandwidth dependent upon the distance of external target, amplitude, and frequency of current modulation. The basic theoretical details and a mathematical model are presented for the developed measurement principle. Experimental results with the system working as a vibrometer to measure a target vibration of amplitude lambda/5 (137.5 nm) with a mean peak-to-peak error of 2.4 nm just by pointing the laser diode onto the target and applying some signal processing are also demonstrated.Postprint (author's final draft

Overview of biofluids and flow sensing techniques applied in clinical practice

This review summarizes the current knowledge on biofluids and the main flow sensing techniques applied in healthcare today. Since the very beginning of the history of medicine, one of the most important assets for evaluating various human diseases has been the analysis of the conditions of the biofluids within the human body. Hence, extensive research on sensors intended to evaluate the flow of many of these fluids in different tissues and organs has been published and, indeed, continues to be published very frequently. The purpose of this review is to provide researchers interested in venturing into biofluid flow sensing with a concise description of the physiological characteristics of the most important body fluids that are likely to be altered by diverse medical conditions. Similarly, a reported compilation of well-established sensors and techniques currently applied in healthcare regarding flow sensing is aimed at serving as a starting point for understanding the theoretical principles involved in the existing methodologies, allowing researchers to determine the most suitable approach to adopt according to their own objectives in this broad field.This research was supported by the Consejo Nacional de Ciencia y Tecnología (CONACYT) of México through Ph.D. grant 472102 and by the Ministerio de Economía y Competitividad through grant FIS2017-89850R.Peer ReviewedPostprint (author's final draft

Metrologia 3D de superfícies extenses

Postprint (published version

Sensores cromo-fluorogénicos para compuestos potencialmente peligrosos

La presente tesis doctoral titulada "Sensores cromo-fluorogénicos para compuestos potencialmente peligrosos" está centrada en el diseño y la síntesis de dosímetros químicos colorimétricos y de nanopartículas híbridas orgánico-inorgánicas para la detección visual de simulantes de agentes nerviosos y por extensión de los propios agentes nerviosos. La detección de este tipo de sustancias es muy importante debido a su elevada toxicidad y a la posibilidad de que sean utilizadas indiscriminadamente por parte de grupos terroristas. Los ejemplos de sensores químicos para este tipo de sustancias descritos en la literatura son, en su mayoría, sensores o dosímetros químicos fluorogénicos y por tanto requieren para su utilización de equipos relativamente sofisticados. Es por ello que se decidió desarrollar nuevos sistemas colorimétricos que permitieran una detección visual "a simple vista" de este tipo de sustancias químicas. Los agentes nerviosos son compuestos organofosforados que tienen carácter electrofílico y por tanto reaccionan con nucleófilos. Así, en primer lugar, se diseñaron y evaluaron con éxito tres sistemas de recepción con grupos nucleófilos que fueron incluidos en cromóforos de tipo dador-aceptor y que permitieron el desarrollo de tres nuevas familias de reactivos o sondas colorimétricas para la detección de agentes nerviosos. Las dos primeras familias de reactivos colorimétricos desarrollada en esta tesis doctoral esta basada en colorantes de tipo azoico. Haciendo uso de esta nueva aproximación se diseñaron y sintetizaron distintos colorantes azoicos con piridinas como grupos aceptores y se comprobó que eran capaces de reaccionar y por tanto detectar los simulantes de agentes nerviosos empleados en el estudio. La última familia de reactivos colorimétricos esta basada en derivados de diarilmetanol y triarilmetanol, conocidos como carbinoles, y permite una detección visual de los agentes nerviosos mediante la aparición de color a partir de disoluciones incoloras.Royo Calvo, S. (2011). Sensores cromo-fluorogénicos para compuestos potencialmente peligrosos [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11958Palanci

Experiència d'aprenentatge cooperatiu en l'assignatura de lents oftàlmiques

Per tal d'adaptar les Lents Oftàlmiques a l' Espai Europeu d’ Educació Superior, s' ha endegat una experiència que aplica tècniques d'aprenentatge cooperatiu a les pràctiques de l'assignatura per afavorir el desenvolupament d'habilitats comunicatives i treball en equip dels estudiants. S'han elaborat uns guions especials on s'especifiquen uns objectius individuals i uns altres de col·lectius, i on s'estableixen 5 fases a seguir. A més inclouen unes taules de presa de dades i unes qüestions relatives al desenvolupament i/o als resultats obtinguts. Es treballa en grups de tres estudiants. En la FASE I s'adjudica una tasca diferent a cada component del grup, que sol consistir en llegir i fer un esquemaresum d'una part de la pràctica. En la FASE II es posen en comú els continguts, de manera que al final de la fase tots els integrants del grup puguin ser capaços de realitzar la pràctica. En la FASE III prenen conjuntament les dades i fan els càlculs oportuns. En la FASE IV, que sol ser ex-aula, el grup ha d'elaborar un informe conjunt, que inclogui els resultats de mesures i càlculs, i les respostes a les qüestions plantejades. L'informe ha de ser consensuat i signat per cadascun dels membres del grup. La FASE V és la d'avaluació, on aleatòriament un dels components del grup és entrevistat pel professor. La qualificació obtinguda s'adjudica a tots els membres del grup

Consumption study and energy optimization of a typical Valencian house

[EN] This paper reports on the energy consumption study of a typical Valencian house with the aim of achieving a maximum reduction in HVAC energy demand. With this purpose, an extensive simulation project was done by using TRNsys 17 software. Previously, all necessary data were collected and studied. Then, an energy simulation of the original house was performed, hence obtaining experimental evidence to verify the predictive capability of the developed energy model. Subsequently, the energy optimization strategy was proposed and the measures to improve the energy demand were implemented on the model, in order to reach a zero HVAC demand. Finally, the following conclusions were obtained: energy model adjustment is fundamental for reproducing the specific thermal behavior of the studied building and for the optimization of the energy demand and secondly, enhancing the building envelope is the most effective proposal for achieving the reduction in the HVAC requirements for the building.[ES] El documento describe el estudio energético desarrollado con el objetivo de lograr una máxima reducción de la demanda de energía para finalmente obtener un cero consumo de climatización. Con este objetivo se ha llevado a cabo un trabajo muy extenso de simulación con el uso del software TRNsys 17 con los siguientes pasos consecutivos: Registro previo de todos los datos climáticos y constructivos registran del edificio original es llevado a cabo, obteniendo de esa manera la comparación experimental para comprobar la capacidad predictiva del modelo energético desarrollado. La estrategia de optimización energética se planea cuidadosamente y las propuestas de mejora se aplican en el modelo con el análisis detallado de los resultados. Se obtienen las siguientes conclusiones: En el ajuste del modelo energético es fundamental reproducir el comportamiento térmico específico del edificio estudiado En la optimización de la demanda de energía, el aislamiento de la envolvente del edificio es la propuesta más eficaz para lograr la reducción de los requerimientos energéticos del edificio.Martínez-Ibernón, A.; Royo, R.; Tormo Esteve, S. (2018). Consumption study and energy optimization of a typical Valencian house. CRC Press. 295-300. http://hdl.handle.net/10251/20136129530