Microoptics for efficient redirection of sunlight

Ray-tracing calculations are employed to identify basic design rules for the configuration of microstructured daylighting systems. The results show the advantage of combinations of lenslike geometries in comparison to conventional microprism arrays regarding the overall light redirection efficiency as well as the producibility and cost efficiency. Measurements at silicone prototypes and large scale industrially produced acrylic panels confirmed the simulation results. Optimization leads to free-form geometries which can further be improved by selective roughening of specific microsurfaces.