Illumination design patterns for homogenization and color mixing

Abstract

Abstract In illumination optics, color mixing is a key design task, but the realization can be a challenge. While tunable light sources based on multiple LEDs are commonplace, color homogenization is just as important for white LEDs, due to their spatial and angular color variation. In this tutorial, we first look at color mixing from an abstract, phase space-based viewpoint. From there, we derive a taxonomy of color mixing problems: How is the multi-color light source composed? What kind of homogeneity is required in the target? How is the homogenization influenced by source and target étendue? We categorize these problems and we present a toolbox: A selection of optical design elements, e.g. mixing rods and fly’s eye arrays, and we show for each design pattern how it fits into the taxonomy.