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Aproximadamente 18 registro(s) hasta el momento: (journal)

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Recurso libre

Retinal image quality assessment through a visual similarity index
Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Vázquez Ferri, Carmen - Mas Candela, David

Formato:	info:eu-repo/semantics/article
Enlaces:	Retinal image quality is commonly analyzed through parameters inherited from instrumental optics. These parameters are defined for ‘good optics’ so they are hard to translate into visual quality metrics. Instead of using point or artificial functions, we propose a quality…
Fecha:	2013-05-13
Recurso:	RUA Docencia

Recurso libre

High-efficiency silver-halide sensitized gelatin holograms with low absorption and scatter
Beléndez Vázquez, Augusto - Neipp López, Cristian - Flores, Marcos - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	We report for the first time the results of a comparative performance study of silver-halide sensitized gelatin (SHSG) holograms recorded in the familiar Agfa 8E75 HD plates and the new BB-640 plates manufactured by Holographic Recording Technologies. High diffraction efficiency…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

Optical surface reconstruction technique through combination of zonal and modal fitting
Espinosa Tomás, Julián - Mas Candela, David - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Videokeratometers and Scheimpflug cameras permit accurate estimation of corneal surfaces. From height data it is possible to adjust analytical surfaces that will be later used for aberration calculation. Zernike polynomials are often used as adjusting polynomials, but they have shown…
Fecha:	2010-05-03
Recurso:	RUA Docencia

Recurso libre

Copying low spatial frequency holograms in silver halide emulsions: the influence of the bleach bath
Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio - Beléndez Vázquez, Augusto - Campos Coloma, Juan - Yzuel Giménez, María Josefa

Formato:	info:eu-repo/semantics/article
Enlaces:	We present an available and low cost technique for the production of binary-phase diffractive optical elements designed by digital methods. We produce binary-amplitude holograms making use of a high-resolution graphic device. They are used as binary masks which are copied…
Fecha:	2009-05-20
Recurso:	RUA Docencia

Recurso libre

Development of a unified FDTD-FEM library for electromagnetic analysis with CPU and GPU computing
Francés Monllor, Jorge - Bleda Pérez, Sergio - Gallego Rico, Sergi - Neipp López, Cristian - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The present paper describes an optimized C++ library for the study of electromagnetics. The implementation is based on the Finite-Difference Time-Domain method for transient analysis, and the Finite Element Method for electrostatics. Both methods share the same core and are…
Fecha:	2013-05-07
Recurso:	RUA Docencia

Recurso libre

Fresnel diffraction in a theoretical eye: a fractional Fourier transform approach
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Mas Candela, David - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work, we have applied the fractional Fourier transform to obtain the Fresnel diffraction patterns in a theoretical eye. The FRT approach to Fresnel diffraction is easily implemented in a Gullstrand-Emsley theoretical eye, and it allows us to obtain…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Diffuse-object holograms in silver halide sensitized gelatin
Fimia Gil, Antonio - Pascual Villalobos, Inmaculada - Carretero López, Luis - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	This paper deals with diffuse-object holograms recorded in silver halide sensitized gelatin. Both the diffraction efficiency and the signal-to-noise ratio when reconstruction is done with different wavelengths are measured. The experimental results we obtained show that new theoretical models for…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

Method for the characterization of hologram processing
Bányász, Istvan - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	A novel method for the characterization of the processing of both absorption and phase holograms is proposed. Differently from the previous models, the square root of the diffraction efficiency of the processed hologram was directly related to the amplitude of…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Complete algorithm for the calculation light patterns inside the ocular media
Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos - Miret Marí, Juan José - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo

Formato:	info:eu-repo/semantics/article
Enlaces:	Realistic mathematical models are of great importance for studying the optical performance of the human eye. Light propagation algorithms provide robust methods to calculate field distributions inside a homogeneous medium, and thus they can be applied to the study of…
Fecha:	2007-10-08
Recurso:	RUA Docencia

Recurso libre

10.

Copying low spatial frequency diffraction gratings in photopolymer as phase holograms
Pascual Villalobos, Inmaculada - Márquez Ruiz, Andrés - Beléndez Vázquez, Augusto - Fimia Gil, Antonio - Campos Coloma, Juan - Yzuel Giménez, María Josefa

Formato:	info:eu-repo/semantics/article
Enlaces:	Photopolymers are studied as holographic recording materials for recording computer-generated phase holograms. The recording was performed using a holographic copying process, in which the master is produced by means of a high resolution graphic device. To our knowledge it is…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

11.

Angular responses of the first diffracted order in over-modulated volume diffraction gratings
Neipp López, Cristian - Álvarez López, Mariela Lázara - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Sheridan, John T. - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Kogelnik's coupled-wave (CW) theory has been used for decades to predict the diffraction efficiency of volume diffraction gratings. Although this theory has been applied with success to volume diffraction gratings recorded under a great variety of experimental conditions, its predictions…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

12.

Imaging in white light with a thick-phase transmission holographic doublet
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	An afocal two-element holographic imaging system is presented. This system can be used to work in white light. The holographic optical elements (holographic lenses) are made as thick phase holograms on silver halide sensitized gelatin (SHSG) and they present a…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

13.

Noise gratings in thick-phase holographic lenses
Beléndez Vázquez, Augusto - Fuentes Rosillo, Rosa - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	An experimental analysis of noise gratings in holographic lenses is presented. Lenses are recorded as thick-phase holograms in bleached silver halide emulsion. The authors calculated noise grating efficiency by using the diffraction efficiency in points across a lens diameter. They…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

14.

Diffractive and interferometric methods to characterize photopolymers with liquid crystal molecules as holographic recording material
Gallego Rico, Sergi - Márquez Ruiz, Andrés - Ortuño Sánchez, Manuel - Francés Monllor, Jorge - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	We present two methods, interferometry at the zero spatial frequency limit and analysis of diffracted orders for very low spatial frequency gratings, to characterize photopolymers with dispersed nematic liquid crystals. These methods provide us with real time information about the…
Fecha:	2012-07-04
Recurso:	RUA Docencia

Recurso libre

15.

Mixed phase-amplitude holographic gratings recorded in bleached silver halide materials
Neipp López, Cristian - Pascual Villalobos, Carolina - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The coupled wave theory of Kogelnik has given a well-established basis for the comprehension of how light propagates inside a volume hologram. This theory gives a good approximation for the diffraction efficiency of both volume phase holograms and volume absorption…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

16.

The computation and statistical analysis of aberrational diffraction patterns in holographic optical elements
Carretero López, Luis - Fimia Gil, Antonio - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Three numerical methods for calculating the point spread function for holographic optical elements in the presence of aberrations are analyzed. The starting point for the analytical formulation of the diffraction theory of aberrations for holographic optical elements is the Fresnel-Kirchhoff…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

17.

Hybrid ternary modulation applied to multiplexing holograms in photopolymers for data page storage
Fernández Varó, Elena - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Fuentes Rosillo, Rosa - García Llopis, Celia - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Holographic data storage is a new optical technology, which allows an important number of bits to be stored in a recording material. In this paper, holographic data pages were stored in a polyvinyl alcohol/acrylamide (AA) photopolymer layer, using a peristrophic…
Fecha:	2011-07-18
Recurso:	RUA Docencia

Recurso libre

18.

Tensorial split-field finite-difference time-domain approach for second- and third-order nonlinear materials
Francés Monllor, Jorge - Tervo, Jani - Márquez Ruiz, Andrés

Formato:	info:eu-repo/semantics/article
Enlaces:	The split-field finite-difference time-domain (SF-FDTD) method for one-dimensionally periodic structures is extended to include the coefficient-tensor description of second- and third-order nonlinear-optical media. A set of nonlinear equations related to the split-field values of the electric field is established. An…
Fecha:	2013-09-06
Recurso:	RUA Docencia