Illumination light pipe using micro-optics as diffuser

A scattering light pipe has been designed for a non- conventional illumination system. The spatial distribution of the light is controlled by diffusers which are deposited on top of the pipe faces. The first realized samples have used a scattering paint as diffuser which has good optical properties but is unsuited to fabrication. Diffusers based on micro-optics have the potential to replace favorably classical Lambertian diffusers. Micro-optical diffusers (MODs) allow the generation of perfectly defined scattering distributions which are well adapted for the design of an optimized light pipe. A further advantage of such surface relief elements is their potential for cheap mass production. The strengths and limits of micro-prisms, micro- lenses, and gratings are evaluated in view of their use as diffusers. Finally a proposition for an optimized design of the illumination light pipe is presented.