Stereolithography Apparatus (SLA) Prototyping of Aspheric Surfaces for Automotive Illumination

Thick optical waveguides (or light pipes) which utilize optimized aspheric surfaces can greatly improve illumination efficiency in radio and instrument cluster lighting systems.[1] Stereolithography (SL) is the ideal way to generate fast, cheap light pipe system prototypes. However, to effectively analyze SLA produced aspheric light pipes, the material and physical effects of SLA fabrication have to be determined and isolated from the part geometry. Therefore, this paper presents optical characterization of SLA fabricated light pipes and a comparison of an injection molded aspheric light pipe to SLA fabricated aspheric light pipes. The feasibility of effectively using SLA prototyping for precise aspheric surfaces is discussed.