Optimizing angle-to-area-converting, light-piping systems using surface features

In this paper, we investigate how to improve the uniformity of the spatial distribution of the illuminance at the output plane for angle-to-area-converting, light-piping systems through the introduction of cyclical surface features. A superposition approach is used for studying uniformity. Improvements in uniformity for square-to-circle and rectangle-to-circle lightpipe configurations are demonstrated for a short package length.