Person:
Álvarez Fernández-Balbuena, Antonio

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First Name
Antonio
Last Name
Álvarez Fernández-Balbuena
URI
https://hdl.handle.net/20.500.14352/79920
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
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2006 - 20095
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End date: 2009 × Subject: 535 ×

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Now showing 1 - 5 of 5
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    High efficiency 90° elbow for light guides
    (Nonimaging Optics and Efficient Illumination Systems V, 2008) Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; García Fernández, Berta; Bernabeu Martínez, Eusebio; Winston, Ronald; Koshel, R. John
    Transmission of light through a 90 degrees elbow in a hollow light guide is an important step in the development of natural lighting applications. In this paper we present a new design that has more than 260% higher efficiency in flux transfer than a standard bending system for hollow and aluminum light guides. The clue of this new system is to minimize the light angle at the output of the elbow, in such way that it is possible to guide light at higher distances because of the fewer reflections in the light guide. The system works properly for prismatic light guides but is also suitable for aluminum guides where the reduction of reflections permit the use of cheaper aluminum or the increase in length maintaining flux transfer. Also this reduction of reflections in aluminum light guide derives in less change of chromatic coordinates.
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    Improved spatial integrator with axicon-dioptric elements
    (Optical Engineering, 2006) Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; Alda, Javier; Bernabeu Martínez, Eusebio
    The flux transfer efficiency of an optical array with spatial integration has been improved by adding a new element at the input surface. The optical characteristics of the input surfaces of the individual units do not affect the spatial integration property. We propose to fill this input surface with a nested optical array designed to transfer as much energy as possible to the plane of the synthetic image of the spatial integrator array. Several designs for the individual units of this array are discussed. The most promising design consists of a cylindrical axicon-diopter element. This element has been simulated, fabricated, and tested, showing the expected improvement in performance.
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    Louvers design for LED displays for sunny days
    (Displays, 2007) Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; Alda Serrano, Javier; Bernabeu Martínez, Eusebio
    The use of louvers attached to variable information display needs to be optimized taking into account different intrinsic and extrinsic parameters. The analysis of the performance of the display–louvers system takes into account the location, orientation, and daily and seasonal variations. The observation of the system is divided depending on the distance of observation. The far distance vision performance use the background luminance. The medium distance performance needs the use of the Contrast Sensitivity Function of the eye.
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    Ideal 3D asymmetric concentrator
    (Solar Energy, 2009) García Botella, Ángel; Álvarez Fernández-Balbuena, Antonio; Vázquez Moliní, Daniel; Bernabeu Martínez, Eusebio
    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric – without rotational or translational symmetry – concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator.
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    Hyperparabolic concentrators
    (Applied Optics, 2009) García Botella, Ángel; Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; Bernabeu Martínez, Eusebio; González Cano, Agustín
    We present a family of three-dimensional concentrators constructed from the photic field generated by a Lambertian emitter. The profile of these concentrators is obtained from the field lines for a two-dimensional truncated wedge and is based on the union between a hyperbola and a tilted parabola. By revolution of this profile, we obtain hyperparabolic concentrators (HPCs). In the limiting case when the focal length of the hyperbola becomes the radius of the exit aperture, the HPC becomes the well-known compound parabolic concentrator. On the other hand, when the focal length of the hyperbola becomes infinite, the HPC achieves the thermodynamic limit of concentration.