Person: Álvarez Fernández-Balbuena, Antonio
Loading...
First Name
Antonio
Last Name
Álvarez Fernández-Balbuena
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
6 results
Search Results
Now showing 1 - 6 of 6
Item Smooth light extraction in lighting optical fibre(Illumination Optics II, 2011) Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; García Botella, Ángel; Martínez Antón, Juan Carlos; Bernabeu Martínez, Eusebio; Kidger, Tina E.; David, StuartRecent advances in LED technology have relegated the use of optical fibre for general lighting, but there are several applications where it can be used as scanners lighting systems, daylight, cultural heritage lighting, sensors, explosion risky spaces, etc. Nowadays the use of high intensity LED to inject light in optical fibre increases the possibility of conjugate fibre + LED for lighting applications. New optical fibres of plastic materials, high core diameter up to 12.6 mm transmit light with little attenuation in the visible spectrum but there is no an efficient and controlled way to extract the light during the fibre path. Side extracting fibres extracts all the light on 2π angle so is not well suited for controlled lighting. In this paper we present an extraction system for mono-filament optical fibre which provides efficient and controlled light distribution. These lighting parameters can be controlled with an algorithm that set the position, depth and shape of the optical extraction system. The extraction system works by total internal reflection in the core of the fibre with high efficiency and low cost. A 10 m length prototype is made with 45° sectional cuts in the fibre core as extraction system. The system is tested with a 1W white LED illuminator in one side.Item Optics detailed analysis of an improved collimation system for LED light sources(Illumination Optics II, 2011) González Montes, Mario; Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; García Botella, Ángel; Bernabeu Martínez, Eusebio; Kidger, Tina E.; David, StuartThroughout present study will be discusses the influence of the manufacturing margins, adjustment precision and ray model accuracy of a collimating LED unit in the overall system performance. It will be also analyzed the angular performance and the collimated in relation to the relative position of the LED and the collimator's dimensions. Finally the results will be compared with existing publications in this field.Item High-efficiency light-emitting diode collimator(Optical Engineering, 2010) Vázquez Molini, Daniel; González Montes, Mario; Álvarez Fernández-Balbuena, Antonio; Bernabeu Martínez, EusebioWe describe an analytical and numerical method to design and optimize LED (light-emitting diode) collimators. The optimization process is confirmed by optical simulations and experimental measurements of a scaled prototype. The collimator's definitive geometry and design parameters rely on the LED's emitting characteristics and the employed collimator material. The resulting parabolic-elliptical-based collimator shows an optimum performance and a compact structure with requirement for mirrored surfaces.Item Light output losses of prism light guides(Optical Systems Design 2012, 2012) García Fernández, Berta; Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; Bernabeu Martínez, EusebioCylindrical prismatic hollow light guides are able to transmit daylight properly into the spaces of a building in which natural light has a difficult access. Transmission through the guide depends on the optical characteristics of the material, the shape of the guide and the fidelity of the geometry in prisms structure. It is important to analyse the micro-structure prism imperfections of the surfaces such as the existence of a curved area on peaks prism which modify the behaviour of the prism film; these imperfections, change the optical path and therefore the rays are directed to other directions instead of undergoing total internal reflections. In this paper, several cylindrical guides made of transparent dielectric material characterized with an absorption factor have been developed. A numerical analysis has been carried out by software tools to analyse the flux distribution in the light guidance system comparing its efficiency by optical analysis in different simulations. These simulations include high reproductively prism related to the light pipe’s material and optical properties including a study of the impact of imperfect geometry which is necessary to allow rigorous comparisons with the experimental simulations. The simulated results have been compared with experimental data obtained through real scale analysis. The experimental measurements have revealed effectiveness of 66.7 % in the aspect ratio of 30.Item Improved spatial integrator with axicon-dioptric elements(Optical Engineering, 2006) Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; Alda, Javier; Bernabeu Martínez, EusebioThe 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.Item 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. JohnTransmission 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.