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Aproximadamente 77 registro(s) hasta el momento: (journal)

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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

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

Efficiency of thick phase holograms in the presence of shear-type effects due to processing
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Based on the results of the coupled-wave theory the diffraction efficiency is calculated for thick phase transmission holographic gratings taking into account the chemical processing of the recording material. Three effects of processing are considered: variations in the average refractive…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Silver halide (sensitized) gelatin in Agfa-Gevaert plates: the optimized procedure
Fimia Gil, Antonio - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Silver halide sensitized gelatin (SHSG) is one of the most promising techniques for the fabrication of transmission holographic optical elements, achieving relatively high sensitivity of photographic material with the low scattering and high light stability of dichromated gelatin. In this…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Influences of recording geometry parameters on diffraction efficiency in bleached silver halide transmission holograms
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	The experimental results of diffraction efficiency as a function of the geometrical disposition of recording beams in bleached silver halide transmission thick-holographic gratings are presented. Two variables have been used to relate these results with certain geometric parameters. These variables…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Statistical model for noise gratings recorded in volume holograms
Carretero López, Luis - Fimia Gil, Antonio - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	A statistical model is used to study the formation of noise gratings in holograms and the mechanism that causes radiation scattering in them. The theoretical model presented describes noise scattering in terms of diffraction due to the high number of…
Fecha:	2009-02-03
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

Nonlinear response of photopolymers for holography: copolymerization process
Fimia Gil, Antonio - Carretero López, Luis - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	A model is proposed which allows us to obtain the diffraction efficiency of photopolymeric materials with a nonlinear response to the refraction index, using the equations on the evolution of copolymerization reactions as a base. The photochemical material being analysed…
Fecha:	2009-02-03
Recurso:	RUA Docencia

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

10.

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

11.

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

12.

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

13.

Axial irradiance and entropy of holographic optical elements under illumination with quasi-monochromatic light
Carretero López, Luis - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	The chromatic sensitivity of holographic optical elements for use in optical interconnect systems is quantified using an entropy merit function. The influence of broad-band illumination on axial irradiance and intensity is studied showing that the best imaging point obtained with…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

14.

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

15.

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

16.

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

17.

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

18.

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

19.

Holographic noise gratings for analysing and optimizing photochemical processings in bleached silver halide emulsions
Carretero López, Luis - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Recording noise gratings with single-beam exposures in bleached silver halide emulsions is used as a holographic spectroscopy technique in order to analyse and optimize photochemical processing. In particular, rehalogenating type bleachings are analysed by measuring the transmittance through the recorded…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

20.

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

21.

Stabilization of volume gratings recorded in polyvinyl alcohol-acrylamide photopolymers with diffraction efficiencies higher than 90%
Gallego Rico, Sergi - Neipp López, Cristian - Ortuño Sánchez, Manuel - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Obtaining holographic volume gratings with high diffraction efficiencies that can be used under white light has been a serious problem for the polyvinyl alcohol-acrylamide-based photopolymers developed by other researchers. In this paper we propose to eliminate the residual monomer in…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

22.

Weighted Zernike polynomial fitting in steep corneas sampled in Cartesian grid
Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Surfaces with radial structure do not fit well to squared detectors or sampling matrices. Cartesian grid sampling provides a different density of nodes in sectors. Zernike polynomials are a complete set of orthogonal polynomials defined on a unit disk often…
Fecha:	2011-02-21
Recurso:	RUA Docencia

Recurso libre

23.

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

24.

Holographic optical elements in the presence of spherical aberration and focus error: some remarks on imaging quality
Beléndez Vázquez, Augusto - Carretero López, Luis - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	When aberrations are small, it is possible to use wave aberration variance to obtain the position of the best image plane in both conventional and holographic optical systems. However, when aberrations increase, this measurement is not sufficient and it does…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

25.

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

26.

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

27.

High-efficiency volume holograms recording on acrylamide and N,N'methylene-bis-acrylamide photopolymer with pulsed laser
Gallego Rico, Sergi - Ortuño Sánchez, Manuel - García Llopis, Celia - Neipp López, Cristian - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	In order to achieve a better understanding of the mechanisms of hologram formation and higher diffraction efficiencies in volume gratings stored in acrylamide based photopolymers, a crosslinker (N,N'methylene-bis-acrylamide) has been incorporated in the photopolymer to record holograms by pulsed laser…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

28.

Effect of the glass substrate on the efficiency of the different orders that propagate in a transmission sinusoidal diffraction grating
Neipp López, Cristian - Sheridan, John T. - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work we study the effect of the glass substrate on the efficiencies of the different orders that propagate inside a transmission sinusoidal diffraction grating. Holographic optical elements are usually recorded on a photosensitive medium deposited on to a…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

29.

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

30.

The influence of the procedure on the dynamic range of bleached silver halide emulsions
Neipp López, Cristian - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

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. Using Kogelnik's coupled-wave theory we shall obtain information about the…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

31.

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

32.

Holographic lens recorded on photopolymers: fabrication and study of the image quality
García Llopis, Celia - Rodríguez, Jesús D. - Fernández Varó, Elena - Camps Sanchis, Vicente Jesús - Fuentes Rosillo, Rosa - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	In recent years, holographic optical elements have been introduced in different applications such as high-density data storage, interconnections, spatial and temporal filters and three-dimensional displays. Simultaneously, more sensitive, efficient and durable holographic materials have been developed. Thus it is necessary…
Fecha:	2009-11-24
Recurso:	RUA Docencia

Recurso libre

33.

Colorimetric and spectral evaluation of the optical anisotropy of metallic and pearlescent samples
Chorro Calderón, Elísabet - Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Campos Acosta, Joaquín - Pons Aglio, Alicia

Formato:	info:eu-repo/semantics/article
Enlaces:	The visual and optical anisotropies of metallic and pearlescent samples have been evaluated using a multi-gonio-spectrophotometer and by adapting a gonio-template over the instrument aperture for measuring the relative spectral reflectance factor when the sample is rotated around an axis…
Fecha:	2010-02-04
Recurso:	RUA Docencia

Recurso libre

34.

Blinking kinematics description through non-invasive measurement
Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Doménech Amigot, Begoña - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Spontaneous eye blinking is a complex process, which implies the joint actions of the eyelid muscles and the eye globe. These actions provoke the eyelid closure and simultaneous eye retraction into the orbit. Recently, the authors presented a non-invasive technique…
Fecha:	2011-02-16
Recurso:	RUA Docencia

Recurso libre

35.

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

36.

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

37.

Left-handed metamaterial coatings for subwavelength-resolution imaging
Zapata Rodríguez, Carlos Javier - Pastor Calle, David - Martínez Martínez, Luis Enrique - Miret Marí, Juan José

Formato:	info:eu-repo/semantics/article
Enlaces:	We report on a procedure to improve the resolution of far-field imaging by using a neighboring high-index medium that is coated with a left-handed metamaterial. The resulting plot can also exhibit an enhanced transmission by considering proper conditions to retract…
Fecha:	2013-11-14
Recurso:	RUA Docencia

Recurso libre

38.

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

39.

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

40.

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

41.

Corneal primary aberrations compensation by oblique light incidence
Espinosa Tomás, Julián - Mas Candela, David - Kasprzak, Henryk T.

Formato:	info:eu-repo/semantics/article
Enlaces:	The eye is not a centered system. The line of sight connects the fovea with the center of the pupil and is usually tilted in the temporal direction. Thus, off-axis optical aberrations, mainly coma and oblique astigmatism, are introduced at…
Fecha:	2009-09-04
Recurso:	RUA Docencia

Recurso libre

42.

Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings
Ferrero Turrión, Alejandro - Rabal Almazor, Ana María - Campos Acosta, Joaquín - Martínez Verdú, Francisco Miguel - Chorro Calderón, Elísabet - Perales Romero, Esther - Pons Aglio, Alicia - Hernanz Sanjuán, María Luisa

Formato:	info:eu-repo/semantics/article
Enlaces:	A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description…
Fecha:	2013-01-10
Recurso:	RUA Docencia

Recurso libre

43.

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

44.

Holographic collimator of diameter 200 mm in silver halide sensitized gelatin
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we present the theoretical analysis and experimental results of a holographic collimator made in silver halide sensitized gelatin. Diffraction efficiency up to 70% over the whole plate and wave aberration as low as 20-lambda in the maximum…
Fecha:	2009-02-09
Recurso:	RUA Docencia

Recurso libre

45.

A two step method for recording holographic optical elements with partially coherent light
Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	We propose a two step method which enables us to obtain transmission Holographic Optical Elements of high diffraction efficiency as well as a good signal-to-noise relation. By means of a device using partially coherent light, a master Holographic Optical Element…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

46.

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

47.

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

48.

Geometrical Optics and Riemannian Geometry
Carretero López, Luis - Mateos Álvarez, Felipe - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The methods of differential geometry are used with the assumption that rays of light follow geodesic trajectories in a space whose metric is determined by the refraction index. Keeping this in mind, we show that these hypotheses are equivalent to…
Fecha:	2009-03-20
Recurso:	RUA Docencia

Recurso libre

49.

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

50.

Clinical validation of an algorithm to correct the error in the keratometric estimation of corneal power for normal eyes
Piñero Llorens, David Pablo - Camps Sanchis, Vicente Jesús - Mateo Pérez, Verónica - Ruiz Fortes, Pedro

Formato:	info:eu-repo/semantics/article
Enlaces:	To validate clinically an algorithm for correcting the error in the keratometric estimation of corneal power by using a variable keratometric index of refraction (nk) in a normal healthy population.
Fecha:	2012-10-30
Recurso:	RUA Docencia

Recurso libre

51.

Number of discernible colors for color-deficient observers estimated from the MacAdam limits
Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Maciel Linhares, João Manuel - Cardoso Nascimento, Sérgio Miguel

Formato:	info:eu-repo/semantics/article
Enlaces:	We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65,…
Fecha:	2011-09-20
Recurso:	RUA Docencia

Recurso libre

52.

Overmodulation control in the optimization of a H-PDLC device with ethyl eosin as dye
Ortuño Sánchez, Manuel - Riquelme Morell, Marina - Gallego Rico, Sergi - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The response of a H-PDLC device is improved by means of a two-step method. First, component optimization—initiator system, crosslinker, and cosolvent—enables the diffraction efficiency of the hologram to be maximized. Second, the use of N-methyl-2-pyrrolidone in combination with N-vinyl-2-pyrrolidone prevents…
Fecha:	2013-12-04
Recurso:	RUA Docencia

Recurso libre

53.

Propagation and phase reconstruction of ocular wavefronts with SAR techniques
Rouarch, Jessica - Espinosa Tomás, Julián - Miret Marí, Juan José - Mas Candela, David - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/preprint
Enlaces:	In this communication, we report a new method to determine the wavefront aberration function of personalized eyes. We obtain corneal surface data and axial lengths for different eyes. With these data, we construct a diffractive model of a human eye,…
Fecha:	2008-03-06
Recurso:	RUA Docencia

Recurso libre

54.

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

55.

Model for analyzing the effects of processing on recording material in thick holograms
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	A new model to describe the influences of chemical processing on thick holograms is presented. The model is based on three hypotheses about the behaviour of holographic recording material during processing. Thickness variations and shear-type effects that are due to…
Fecha:	2009-01-22
Recurso:	RUA Docencia

Recurso libre

56.

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

57.

Thick phase holographic gratings recorded on BB-640 and PFG-01 silver halide materials
Neipp López, Cristian - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Photographic emulsions are still widely used to record holographic optical elements. In particular, if high diffraction efficiencies are needed, phase volume holograms are preferably recorded on these emulsions. Two particular techniques producing high-quality volume phase holograms are fixation-free rehalogenating bleaching…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

58.

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

59.

Magnification and visual acuity in highly myopic phakic eyes corrected with an anterior chamber intraocular lens versus by other methods
García, Mónica - González Pérez, Concepción - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	To calculate retinal magnification and visual acuity in highly myopic phakic eyes corrected with anterior chamber intraocular lenses (IOLs) versus correction by other methods. Relative retinal magnification (RRM) was used to study changes in retinal image size induced by different…
Fecha:	2009-01-29
Recurso:	RUA Docencia

Recurso libre

60.

New theoretical matrix formula for intraocular lens calculation using the optimal bending factor
Fimia Gil, Antonio - Alió y Sanz, Jorge L. - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	By applying Gaussian optics we propose a new matrix formula model for intraocular lens (IOL) calculation that yields not only IOL optical power for a particular eye but also an evaluation of the bending factor of different IOL optical designs.…
Fecha:	2009-01-29
Recurso:	RUA Docencia

Recurso libre

61.

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

62.

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

63.

Custom designed dynamic videokeratometer
Mas Candela, David - Kowalska, Malgorzata A. - Espinosa Tomás, Julián - Kasprzak, Henryk T.

Formato:	info:eu-repo/semantics/article
Enlaces:	The human eye is a complex dynamic system that undergoes fine rotations and deformations. Usually information about the eye globe deformation and micromovements are averaged and lost when using commercial measuring devices, although they provide important information about the eye’s…
Fecha:	2010-02-25
Recurso:	RUA Docencia

Recurso libre

64.

Birefringence of cellotape: Jones representation and experimental analysis
Beléndez Vázquez, Augusto - Fernández Varó, Elena - Francés Monllor, Jorge - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we analyze a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyzer is used to study the effect on the polarization state of…
Fecha:	2010-03-22
Recurso:	RUA Docencia

Recurso libre

65.

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

66.

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

67.

Diagnostic validity of clinical signs associated with a large exophoria at near
Cacho Martínez, Pilar - García Muñoz, Ángel - Ruiz Cantero, María Teresa

Formato:	info:eu-repo/semantics/article
Enlaces:	Purpose. To analyze the diagnostic validity of accommodative and binocular tests in a sample of patients with a large near exophoria with moderate to severe symptoms. Methods. Two groups of patients between 19 and 35 years were recruited from a…
Fecha:	2013-11-06
Recurso:	RUA Docencia

Recurso libre

68.

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

Recurso libre

69.

Pseudoaccommodation and visual acuity with technovision PresbyLASIK and a theoretical simulated Array® multifocal intraocular lens
Illueca Contri, Carlos - Alió y Sanz, Jorge L. - Mas Candela, David - Ortiz Márquez, Dolores - Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Sala Pomares, Esperanza

Formato:	info:eu-repo/semantics/article
Enlaces:	PURPOSE: To compare the visual results of presbyLASIK patients to the best theoretical pseudoaccommodation that could be achieved using a multifocal refractive intraocular lens (IOL) model based on the optical structure of a simulated AMO Array multifocal IOL. METHODS: The…
Fecha:	2008-04-11
Recurso:	RUA Docencia

Recurso libre

70.

First-harmonic diffusion-based model applied to a polyvinyl-alcohol–acrylamide-based photopolymer
Neipp López, Cristian - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Márquez Ruiz, Andrés - Álvarez López, Mariela Lázara - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	The photopolymerization diffusion models give accurate comprehension of the mechanism of hologram formation inside photopolymer materials. Although several models have been proposed, these models share the common assumption that there is an interplay between the processes of monomer polymerization and…
Fecha:	2009-01-22
Recurso:	RUA Docencia

Recurso libre

71.

Comparative study of bleaches applied to BB-640 plates
Neipp López, Cristian - Condeza, Shirley - Campos, Ana María - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The use of bleaching techniques is perhaps one of the most popular methods of creating phase holograms from holographic emulsions. In this paper we will study the influence of the different experimental conditions on the refractive index modulation created inside…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

72.

Low spatial frequency characterization of holographic recording materials applied to correlation
Márquez Ruiz, Andrés - Neipp López, Cristian - Beléndez Vázquez, Augusto - Campos Coloma, Juan - Yzuel Giménez, María Josefa - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Accurate recording of computer-generated holograms (CGH) on a phase material is not a trivial task. The range of available phase materials is large, and their suitability depends on the fabrication technique chosen to produce the hologram. We are particularly interested…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

73.

Temporal response and first order volume changes during grating formation in photopolymers
Kelly, John V. - Gleeson, Michael R. - Close, Ciara E. - O'Neill, Feidhlim T. - Sheridan, John T. - Gallego Rico, Sergi - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	We examine the evolution of the refractive index modulation when recording gratings in an acrylamide based photopolymer. A nonlocal diffusion model is used to predict theoretically the grating evolution. The model has been developed to account for both nonlocal spatial…
Fecha:	2009-02-13
Recurso:	RUA Docencia

Recurso libre

74.

Holographic photopolymer materials: nonlocal polymerization-driven diffusion under nonideal kinetic conditions
Kelly, John V. - O'Neill, Feidhlim T. - Sheridan, John T. - Neipp López, Cristian - Gallego Rico, Sergi - Ortuño Sánchez, Manuel

Formato:	info:eu-repo/semantics/article
Enlaces:	The kinetics of photosensitive polymer holographic recording materials are examined assuming a material that exhibits nonideal kinetic behavior. Previously, a linear relationship between monomer concentration and polymerization was assumed when deriving the nonlocal polymer-driven diffusion (NPDD) model. This is consistent…
Fecha:	2009-02-04
Recurso:	RUA Docencia

Recurso libre

75.

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

Recurso libre

76.

Corneal aberrometric and refractive performance of 2 intrastromal corneal ring segment models in early and moderate ectatic disease
Piñero Llorens, David Pablo - Alió y Sanz, Jorge L. - El Kady, Bassam - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Purpose: To evaluate and compare visual, refractive, and corneal aberrometric outcomes after implantation of 2 types of intrastromal corneal ring segments (ICRS) in eyes with early to moderate ectatic disease. Settings: Vissum Corporation-Instituto Oftalmológico de Alicante, Alicante, Spain. Methods: This…
Fecha:	2010-02-15
Recurso:	RUA Docencia

Recurso libre

77.

Some activities on educational technology innovation in Physics, optics and telecommunications
Arribas Garde, Enrique - Beléndez Vázquez, Augusto - Nájera López, Alberto - Márquez Ruiz, Andrés - Villalba Montoya, José Manuel - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Francés Monllor, Jorge - Álvarez López, Mariela Lázara - Neipp López, Cristian - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	The use of innovative technologies in education offers new possibilities that complement classroom teaching and may also help to improve the quality of education, enabling students to actively participate in the learning process. With this in mind, in 2009 the…
Fecha:	2012-10-01
Recurso:	RUA Docencia