Metabuscador

Filtrado por:

Temas

Año

2009 (11)
2008 (2)
2006 (1)
2005 (3)
2004 (1)
2003 (2)
Más...

Aproximadamente 23 registro(s) hasta el momento: (journal)

Mostrar 10 | 50 | 100 resultados por página

Recurso libre

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

Theoretical and experimental analysis of overmodulation effects in volume holograms recorded on BB-640 emulsions
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Kogelnik's coupled-wave theory has provided a well-established basis for understanding how light propagates inside a volume hologram, giving an accurate approximation of the diffraction efficiency in this type of hologram. In this paper we elaborate on some aspects of the…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

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

Transformation of wavefront aberrations of holographic lenses for a general position of the exit pupil
Beléndez Vázquez, Augusto - Carretero López, Luis - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Equations are derived for determining third-order wavefront aberrations in the plane of the exit pupil from the known aberration in the plane of a holographic lens. Using the transformation equations of wavefront aberration when the plane of the exit pupil…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

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

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

Influence of the gaze-stabilizing eye movements on the quality of the retinal image of the human eye
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Artigas Verde, José María - Felipe Marcet, Adelina

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work we have studied the influence of the gaze stabilizing movements of the eye on the quality of the retinal image of the human eye obtained by double pass methods. The results obtained agree with the expected differences…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Refractive analysis of the human cornea through propagated fields
Illueca Contri, Carlos - Mas Candela, David - Pérez Rodríguez, Jorge - Pons Moreno, Álvaro Máximo - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	A new technique for analysing the optical quality of the human cornea is presented. Corneal maps are obtained through keratographies and then converted into phase maps. The propagated fields generated from this surface are plotted and studied. It is shown…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Silver halide sensitized gelatin holograms in Slavich PFG-01 red-sensitive emulsion
Beléndez Vázquez, Augusto - Neipp López, Cristian - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Silver halide sensitized gelatin (SHSG) is an interesting technique for the production of holographic optical elements. It combines the high sensitivity of photographic emulsions with the well-known low scattering and high diffraction efficiency corresponding to dichromated gelatin. In this paper…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

10.

Comparison of nonlinear characteristics of phase holograms processed by various combinations of developers and bleaching agents
Bányász, Istvan - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Optical densities before bleaching and final Lin curves of planewave phase holograms recorded in Agfa—Gevaert 8E75HD emulsions were measured for various combinations of developers (AAC, Pyrogallol and Catechol) and bleaching agents (R-9 and EDTA). To characterize the processing, the square…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

11.

Optimization of a fixation-free rehalogenating bleach for BB-640 holographic emulsion
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Fixation-free rehalogenating bleaching is an interesting for the production of phase holograms. The shrinkage of the emulsion is reduced in comparison with other bleaching methods (reversal bleaching or rehalogenating bleaching with fixation). In this paper we present experimental results for…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

12.

Bleached silver halide volume holograms recorded on Slavich PFG-01 emulsion: the influence of the developer
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Bleached holograms are one of the most interesting techniques used to produce phase holograms of high quality on photographic emulsions. Of particular interest is the method of fixation-free rehalogenating bleaching. In this paper we will study the influence of the…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

13.

High-energy sensitivity enhancement in panchromatic photopolymers for holography using a mixture of visiblelight photoinitiators
Fimia Gil, Antonio - Mateos Álvarez, Felipe - Mallavia Marín, Ricardo - Blaya Escarre, Salvador - Beléndez Vázquez, Augusto - Sastre Muñoz, Roberto - Amat Guerri, Francisco

Formato:	info:eu-repo/semantics/article
Enlaces:	A new aqueous photopolymer containing the monomers acrylamide, N,N'-methylenbisacrylamide and zinc acrylate, the initiators 4,5-diiodosuccinylfluorescein (2ISF) and methylene blue (MB), and the coinitiator sodium p-toluenesulphinate is described. This formulation exhibits a clear enhancement of the high-energy sensitivity upon irradiation with…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

14.

Fixation-free bleached silver halide transmission holograms recorded on Slavich PFG-01 red sensitive plates
Neipp López, Cristian - Beronich, Emiliano - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Bleaching is one of the most widely used techniques in the production of phase holograms of high quality on photographic emulsion, particularly in rehalogenating techniques without a fixation step. These techniques were very well understood when Agfa 8E75 HD emulsion…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

15.

Scale corrections for faster evaluation of convergent Fresnel patterns
Mas Candela, David - Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Numerical calculation of Fresnel patterns through fast Fourier transforms usually requires an extremely large number of samples in order to fulfil the Nyquist sampling condition. In many applications, the cut-off frequency of the system is much below the limit fixed…
Fecha:	2007-10-02
Recurso:	RUA Docencia

Recurso libre

16.

Near-field light distributions propagated from human corneas: determination of relevant patterns
Mas Candela, David - Pérez Rodríguez, Jorge - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	A procedure to determine the best image range of distances that can be obtained from an aphakic eye is presented. Corneal surfaces are calculated from videokeratographic data. Light distributions at different distances inside the eye are calculated with a near-field…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

17.

Computation and visualization of the MacAdam limits for any lightness, hue angle, and light source
Martínez Verdú, Francisco Miguel - Perales Romero, Esther - Chorro Calderón, Elísabet - Fez Saiz, Dolores de - Viqueira Pérez, Valentín - Gilabert Pérez, Eduardo

Formato:	info:eu-repo/semantics/article
Enlaces:	We present a systematic algorithm capable of searching for optimal colors for any lightness L* (between 0 and 100), any illuminant (D65, F2, F7, F11, etc.), and any light source reported by CIE. Color solids are graphed in some color…
Fecha:	2007-07-11
Recurso:	RUA Docencia

Recurso libre

18.

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

19.

Calculation of the color matching functions of digital cameras from their complete spectral sensitivities
Martínez Verdú, Francisco Miguel - Pujol Ramo, Jaume - Capilla Perea, Pascual

Formato:	info:eu-repo/semantics/article
Enlaces:	We propose a new algorithm to obtain the color matching functions of any digital camera, with correct weights and white balance, from the relative scaling of their complete (3-D) spectral sensitivities obtained from real spectroradiometric data. Thanks to this algorithm,…
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

20.

Color visualization system for near-infrared multispectral images
Vilaseca Ricart, Meritxell - Pujol Ramo, Jaume - Arjona Carbonell, Montserrat - Martínez Verdú, Francisco Miguel

Formato:	info:eu-repo/semantics/article
Enlaces:	The aim of this study is to develop a color visualization system for multispectral images in the near-infrared region (NIR, 800–1000 nm). Samples with the same color or appearance in the visible region, which are therefore indistinguishable to the human
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

21.

Characterization of a digital camera as an absolute tristimulus colorimeter
Martínez Verdú, Francisco Miguel - Pujol Ramo, Jaume - Capilla Perea, Pascual

Formato:	info:eu-repo/semantics/article
Enlaces:	An algorithm is proposed for the spectral and colorimetric characterization of digital still cameras (DSC) which allows them to be used as tele-colorimeters with CIE–XYZ color output, in cd/m2. The spectral characterization consists in the calculation of the color-matching functions…
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

22.

New method for comparing colour gamuts among printing technologies
Perales Romero, Esther - Chorro Calderón, Elísabet - Viqueira Pérez, Valentín - Martínez Verdú, Francisco Miguel - Otero Belmar, Susana - Gracia Bonache, Vicente de

Formato:	info:eu-repo/semantics/article
Enlaces:	The authors have developed a simple method to compare the colour gamuts of different industries (printing, textiles, plastics, etc.) based on representing the reproduced colours in constant lightness L* and hue hab* planes. This method allows the analysis of those
Fecha:	2008-10-31
Recurso:	RUA Docencia

Recurso libre

23.

Optical analysis of PresbyLASIK treatment by a light propagation algorithm
Ortiz Márquez, Dolores - Alió y Sanz, Jorge L. - Illueca Contri, Carlos - Mas Candela, David - Sala Pomares, Esperanza - Pérez Rodríguez, Jorge - Espinosa Tomás, Julián

Formato:	info:eu-repo/semantics/article
Enlaces:	PURPOSE: To evaluate the changes in the optical quality of corneas of hyperopic patients operated using central multifocal presbyLASIK treatment through the study of light patterns around the retinal plane. METHODS: This study included eight hyperopic eyes that underwent central…
Fecha:	2008-02-17
Recurso:	RUA Docencia