Néstor Alonso Arias HernandezUniversity of Pamplona · Departamento de Física y Geología
Néstor Alonso Arias Hernandez
Doctor en Ciencias Naturales (Física)
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36
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Publications (36)
En este trabajo se presenta el diseño y construcción de un microscopio perfilométrico por interferometría de luz blanca, que permite el levantamiento topográfico de objetos con resolución nanométrica. Por medio de un escaneo axial del objeto, se adquiere un conjunto de imágenes con franjas interferométricas deformadas las cuales dan información de...
En este trabajo se presenta el diseño y construcción de un microscopio perfilométrico por interferometría de luz blanca, que permite el levantamiento topográfico de objetos con resolución nanométrica. Por medio de un escaneo axial del objeto, se adquiere un conjunto de imágenes con franjas interferométricas deformadas las cuales dan información de...
En este trabajo se presenta el diseño y construcción de un microscopio perfilométrico por interferometría de luz blanca, que permite el levantamiento topográfico de objetos con resolución nanométrica. Por medio de un escaneo axial del objeto, se adquiere un conjunto de imágenes con franjas interferométricas deformadas las cuales dan información de...
Optical tweezers use a highly-focused laser beam to capture and manipulate micro- and nanometric objects. These have been demonstrated to be a promising devices for state-of-the-art research in several fields, such as microbiology and biophysics. The prediction of the optical forces that are present in this phenomenon is a current problem in contin...
En este trabajo se presenta un análisis teórico de la eficiencia de difracción en cristales silenitas tipo BTO, para redes móviles de transmisión, teniendo en cuenta los efectos de acoplamiento [1-5]. En el caso del acoplamiento degenerado en los materiales fotorrefractivos, la eficiencia de difracción depende del espesor del cristal, el coeficient...
From the invention of the Optical Tweezer (OT) in 1986, these devices have been considered as high-level tools for research in the areas such as biology and microbiology. A theoretical study obtaining equations for gradient and scattering forces that exert an OT when the illumination beam is a doughnut-shaped mode TEM∗01 linearly polarized is reali...
Se resuelven las ecuaciones de onda que describen el acoplamiento cuasi-generado que presentan dos haces en un material fotorrefractivo para registros de alta frecuencia. Las ecuaciones de acoplamiento cuasi-generado de dos haces en un material fotorrefractivo dependen del coeficiente de acoplamiento, el tiempo de respuesta del medio, la frecuencia...
Theoretic expressions in the Mie regime for the radiation force on a dielectric sphere captured by TEM00 and TEM*01 mode beams are compared with experimental measurements obtained with a direct force measurement device based on light-momentum detection.
La implementación de las pinzas ópticas en el estudio de procesos biológicos a micro escala, ha demostrado ser útil desde su invención. La predicción del comportamiento de las fuerzas responsables de la captura óptica, sumado al uso actual de haces con vórtices, que han demostrado múltiples ventajas respecto a las trampas convencionales de tipo Gra...
Se resuelven las ecuaciones de onda que describen el acoplamiento cuasi-generado que presentan dos haces en un material fotorrefractivo para registros de alta frecuencia. Las ecuaciones de acoplamiento cuasi-generado de dos haces en un material fotorrefractivo dependen del coeficiente de acoplamiento, el tiempo de respuesta del medio, la frecuencia...
In this work, a method which seeks to locate a radial-color mark attached to the object using the high sensitivity of the phase to determine the position spatial and angular with subpixel resolution due to movement of an object in a 2D scene is presented. The reference pattern is formed by a regular distribution with radially symmetrical of color-R...
A theoretical study on sillenite crystal where it obtained an analytics expression for diffraction efficiency in the on-Bragg regime in transverse configuration (K < 001 >) is realized. It is considered non-mobile transmission gratings. An analysis of diffraction efficiency considering the non-uniformity of gratings, material properties, external p...
The aim of this work is to study and to optimize the diffraction efficiency in sillenite BTO crystals. A theoretical analysis, where the effects of coupling beams are significant, is carried on. In addition, non-mobile transmission gratings are considered. The diffraction efficiency is obtained by using the coupled wave equations in on-Bragg regime...
A method for tracking 3D objects using sensitivity phase of its Fourier transform to determine the position, displacement and orientation of a moving object is presented. The orientation and 3D position of the object from the 3D imaging system with subvoxel accuracy are calculated. A reference pattern should be fixed on the surface of the object an...
A method to extract 3D information using a white light interferometer without using PZT is presented. Instead a positioning system that uses the phase sensitivity of a target periodic is employed. The image treatment realized on the periodic target permits to calculate the relative distance between Mirau objective and object surface. Topographic re...
The main goal of radiation therapy is to provide a high dose of ionizing radiation to the volume defined as injury or target, and reduce the dose to organs or tissues that are close to its anatomy, without subdosificar the treatment area. Due to this, the three-dimensional visualization of the treatment area is of great importance in subsequent sim...
El objetivo principal de la Radioterapia es suministrar una alta dosis de radiacion ionizante al volumen definido como lesion o blanco, y reducir la dosis en los organos o tejidos que por anatomia estan cerca de ella, sin subdosificar la zona de tratamiento. Debido a esto, la visualizacion tridimensional de la zona a tratar, es de gran importancia...
Exact solutions of partial differential equations for circular and rectangular membranes fixed at the edges are presented. Simulations of the vibration modes of a circular membrane are shown in 2 and 3 dimensions and the solution of the wave equation for the rectangular membrane using the method of finite element Both the simulations of the circula...
In this paper we propose a hand-held 3D laser scanner composed of an optical head device to extract 3D local surface information and a stereo vision system with subvoxel precision to measure the position and orientation of the 3D optical head. The optical head is manually scanned over the surface object by the operator. The orientation and position...
We present a method for the visual measurement of the 3D position and orientation of a moving target. Three dimensional sensing is based on stereo vision while high resolution results from a pseudo-periodic pattern (PPP) fixed onto the target. The PPP is suited for optimizing image processing that is based on phase computations. We describe experim...
En este trabajo se implementa un método que permite medir con alta precisión, la posición, el desplazamiento y la orientación en el plano de un objeto móvil. Se fija una mira de referencia al objeto de estudio y se localiza en la escena por medio de un sistema de visión estático con resolución subpixel, en el plano perpendicular al eje óptico (in-p...
La verificación automática de la firma es un área de investigación bien establecida y activa, con numerosas aplicaciones. En contraste, la identificación automática de la firma se le ha dado poca importancia, aunque exista una amplia gama de aplicaciones potenciales que podrían usar la firma como herramienta de identificación. Este trabajo describe...
En este trabajo se implemento un sistema de medida de la topografía de objetos en configuración axial. Este se compone de dos lentes, y brazos de sensado con funcionamiento confocal. El objeto es colocado muy cerca del plano focal de la primera lente, a la salida de la segunda lente el haz es dividido en dos caminos. Un fotodetector es colocado ant...
Este trabajo forma parte de un proyecto de investigación que pretende implementar un sistema de reconstrucción 3D a referencia global. En esta primera parte se diseñó e implementó la cabeza óp-tica necesaria para obtener información tridimensional de la superficie del cuerpo. La cabeza ópti-ca está diseñada bajo los principios de la triangulación l...
A method in order to carry out the verification of handwritten signatures is described. The method keeps in mind global features and local features that encode the shape and the dynamics of the signatures. Signatures are recorded with a digital tablet that can read the position and pressure of the pen. Input patterns are considered time and space d...
A procedure inside the context of artificial vision that estimates the weight in bovine livestock was developed and designed. The input data to the system are images obtained by a videotape camera to color. These images are digitized and preprocessing using filters of elimination of noise; later are implemented and evaluated different segmentation...
A method in order to carry out the verification of handwritten signatures is described. The method keeps in mind global features and local features that encode the shape and the dynamics of the signatures. Signatures are recorded with a digital tablet that can read the position and pressure of the pen. Input patterns are considered time and space d...
A procedure inside the context of artificial vision that estimates the weight in bovine livestock was developed and designed. The input data to the system are images obtained by a videotape camera to color. These images are digitized and preprocessing using filters of elimination of noise; later are implemented and evaluated different segmentation...
A method for the verification of handwritten signatures based on the three-dimensional correlation is proposed. The input images to the algorithms of 3D correlation are those range images obtained from the 3D information formed by the signature path. An optic system based on the laser triangulation method, allows the extracting of 3D information. T...
A method for the verification of handwritten signatures based on the three-dimensional correlation is proposed. The input images to the algorithms of 3D correlation are those range images obtained from the 3D information formed by the signature path. An optic system based on the laser triangulation method, allows the extracting of 3D information. T...
