title: Design of high-efficient freeform LED lens for illumination of elongated rectangular regions.
abstract: We propose a method for the design of an optical element generating the required irradiance distribution in a rectangular area with a large aspect ratio. Application fields include streetlights, the illumination of halls or corridors, and so forth. The design assumes that the optical element has a complex form and contains two refractive surfaces. The first one converts a spherical beam from the light source to a cylindrical beam. The second one transforms an incident cylindrical beam and generates the required irradiance distribution in the target plane. Two optical elements producing a uniform irradiance distribution from a Cree® XLamp® source in rectangular regions of 17 m × 4 m and 17 m × 2 m are designed. The light efficiency of the designed optical element is larger than 83%, whereas the irradiance nonuniformity is less than 9%.
authors.affiliation: Laboratory of Diffraction Optics, Image Processing Systems Institute of the RAS, Molodogvardeyskaya st. 151, Samara 443001, Russia. mikhail@smr.ru
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Moiseev
authors.forename: Leonid L
authors.initials: LL
authors.lastname: Doskolovich
authors.forename: Nikolay L
authors.initials: NL
authors.lastname: Kazanskiy