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Aproximadamente 30 registro(s) hasta el momento: (journal)

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Recurso libre

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

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

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

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

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

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

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

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

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

10.

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

11.

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

12.

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

13.

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

14.

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

15.

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

16.

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

17.

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

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.

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

20.

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

21.

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

22.

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

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

Recurso libre

24.

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

25.

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

26.

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

27.

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

28.

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

29.

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

30.

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