Person: López Alonso, José Manuel
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First Name
José Manuel
Last Name
López Alonso
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
48 results
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Now showing 1 - 10 of 48
Item Multivariate analysis of photonic crystal microcavities with fabrication defects(Photonic Materials, Devices, and Applications, Pts 1 and 2, 2005) Rico García, José María; López Alonso, José Manuel; Alda Serrano, JavierPhotonic crystal microcavities are defined by the spatial arrangement of materials. In the analysis of their spatial temporal mode distributions Finite-Difference Time-Domain (FDTD) methods have proved its validity. The output of the FDTD can be seen as the realizations of a multidimensional statistic variable. At the same time, fabrication tolerances induce an added and unavoidable variability in the performance of the microcavity. In this contribution we have analyzed the modes of a defective photonic crystal microcavity. The location, size, and shape of the cylinders configuring the microcavity are modelled as having a normal distribution of their parametric descriptors. A principal component analysis is applied to the output of the FDTD for a population of defective microcavities. The relative importance of the defects is evaluated, along with the changes induced in the spatial temporal distribution of electromagnetic field obtained from the calculation.Item Spatial characterization of light detectors with nanometric resolution(Proceedings of SPIE, 2004) Alda, Javier; López Alonso, José Manuel; Rico García, José María; Zoido Chamorro, Jesús Manuel; Boreman, GlennThe miniaturization of light detectors in the visible and infrared has produced devices with micrometric and sub-micrometric spatial features. Some of these spatial features are closely linked with the physical mechanism of detection. An example of these devices is an optical antennas. To spatially characterize optical antennas it is necessary to scan a probe beam on the plane of the optical antenna. The mapping of this response is then treated and analyzed. When the response of the antenna is monitorized at visible or near-infrared frequencies, a sub-micron scanning step is necessary. In this paper we show the experimental set-up of a measurement station having a spatial resolution of 50 nanometers. This station is devoted to spatially characterize micrometric detectors, and specially optical antennas. The origin of the uncertainties of the measurement protocol is shown and practically analyzed. This station is also applied for characterizing the temporal, spectral, and polarization sensitivity specifications of light detectors with the previously mentioned resolution.Item Characterization of spatial–temporal patterns in dynamic speckle sequences using principal component analysis(Optical Engineering, 2016) López Alonso, José Manuel; Grumel, Eduardo; Cap, Nelly Lucía; Trivi, Marcelo; Rabal, Héctor; Alda Serrano, JavierAbstract. Speckle is being used as a characterization tool for the analysis of the dynamics of slow-varying phenomena occurring in biological and industrial samples at the surface or near-surface regions. The retrieved data take the form of a sequence of speckle images. These images contain information about the inner dynamics of the biological or physical process taking place in the sample. Principal component analysis (PCA) is able to split the original data set into a collection of classes. These classes are related to processes showing different dynamics. In addition, statistical descriptors of speckle images are used to retrieve information on the characteristics of the sample. These statistical descriptors can be calculated in almost real time and provide a fast monitoring of the sample. On the other hand, PCA requires a longer computation time, but the results contain more information related to spatial–temporal patterns associated to the process under analysis. This contribution merges both descriptions and uses PCA as a preprocessing tool to obtain a collection of filtered images, where statistical descriptors are evaluated on each of them. The method applies to slow-varying biological and industrial processes.Item Development of an algorithm to track blinks from a face video(Proceedings. International Online Symposium of Young Optometrists (SIYO 2022), 2022) Marrakchi, Youssef; López Alonso, José Manuel; Garzón Jiménez, Nuria; González Pérez, Mariano; Universidad de ValenciaThe VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.Item Principal-component characterization of noise for infrared images(Applied Optics, 2002) López Alonso, José Manuel; Alda, Javier; Bernabeu Martínez, EusebioPrincipal-component decomposition is applied to the analysis of noise for infrared images. It provides a set of eigenimages, the principal components, that represents spatial patterns associated with different types of noise. We provide a method to classify the principal components into processes that explain a given amount of the variance of the images under analysis. Each process can reconstruct the set of data, thus allowing a calculation of the weight of the given process in the total noise. The method is successfully applied to an actual set of infrared images. The extension of the method to images in the visible spectrum is possible and would provide similar results.Item Zemax OpticStudio toolbox as a method for visual quality analysis in multifocal contact lenses(Proceedings. International Online Symposium of Young Optometrists (SIYO 2022), 2022) López Raso, Alicia; López Alonso, José Manuel; Burgos Martínez , Mercedes; Ruiz Alcocer, Javier; Goodenoough ,Neil; Universidad de ValenciaThe VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.El Simposio Internacional de Jóvenes Optometristas pretende crear un espacio donde participen conjuntamente jóvenes estudiantes y profesionales de la optometría para facilitar la divulgación de sus investigaciones, así como el contacto y la colaboración. Este libro recopila los resúmenes de las diferentes contribuciones que se presentaron en su cuarta edición, que se celebró del 14 al 28 de noviembre de 2022 en su habitual formato en línea. Se organiza en dos secciones que comprenden las diferentes áreas temáticas de las conferencias, con el objetivo de mejorar la atención en el ámbito de la óptica y la optometría mediante la integración de la investigación en la práctica sanitaria.Item Contact lens fitting through assessment of tear film affectation with different designs by means of thermal camera(Frontiers in Optics / Laser Science, 2020) Durán Prieto, Elena; López Alonso, José ManuelThe study of contact lenses fitting of different designs through the impact on the tear through infrared images of the eye has been carried out. Multifocal lens design behaves as well as traditional ones.Item Comparison of soft toric contact lenses with and without prism ballast stabilization system(2022) Durán Prieto, Elena; González Pascual , María del Mar; Burgos Martínez, Mercedes; Carballo Álvarez, Jesús; López Alonso, José ManuelThe VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.- Project number: 200
Item Desarrollo de herramientas interactivas con acceso remoto para el aprendizaje de óptica biomédica(2015) Cabrera Granado, Eduardo; Gómez Calderón, Óscar; Melle Hernández, Sonia; Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Díaz García, Elena; López Alonso, José Manuel; Arrieta Yañez, FranciscoNuevos documentos de trabajo y consulta basados en IPython Notebook han sido desarrollados con el fin de ofrecer nuevas herramientas para el aprendizaje de la asignatura de Óptica Biomédica de la Facultad de Óptica y Optometría. Este tipo de documentos permiten una mayor libertad al estudiante para explorar distintos temas de Óptica Biomédica facilitando su acceso remoto sin la necesidad de instalar software en su ordenador personal. Item Retinal vascular tortuosity in glaucoma and diabetic retinopathy: correlation with vessel diameters(PROCEEDINGS International Online Symposium of Young Optometrists SIYO 2022, 2022) López Alonso, José Manuel; Igalla El-Youssfi, Asmae; Universidad de ValenciaThe VI International Symposium of Young Optometrists (SIYO 2022) took place from November 14-28 2022 in its usual online format. This conference aims to create a space where young optometry students and optometry practitioners are the protagonists. This book of proceedings contains the abstracts of the different contributions to the conference. Its contents are organizing in two sections: invited and sponsored oral communication and workshops, and free communication. This last section is divided in oral communications and poster communications, comprising the conference’s different thematic areas. The Organizing Committee thanks all the young and senior researchers that have contributed their work to the conference, the members of the Scientific Commettee for their careful reviews of the works and the different enterprises and accademic or offical entities that have sponsored this event.