RT Book, Section T1 High efficiency 90° elbow for light guides A1 Vázquez Moliní, Daniel A1 Álvarez Fernández-Balbuena, Antonio A1 García Fernández, Berta A1 Bernabeu Martínez, Eusebio A2 Winston, Ronald A2 Koshel, R. John AB 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. PB SPIE--The International Society for Optical Engineering SN 978-0-8194-7279-3 YR 2008 FD 2008 LK https://hdl.handle.net/20.500.14352/53373 UL https://hdl.handle.net/20.500.14352/53373 NO © (2008) COPYRIGHT SPIE--The International Society for Optical Engineering.Conference on Nonimaging Optics and Efficient Illumination Systems (5ª. 2008. San Diego, California, EE.UU.). DS Docta Complutense RD 12 may 2025