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Aproximadamente 40 registro(s) hasta el momento: (journal)

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Recurso libre

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

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

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

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

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.

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

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-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

14.

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

15.

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

16.

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

17.

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

18.

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

19.

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

20.

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

21.

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

22.

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

23.

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

24.

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

25.

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

26.

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

27.

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

28.

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

29.

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

30.

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

31.

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

32.

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

33.

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

34.

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

35.

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

36.

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

37.

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

38.

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

39.

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

40.

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