Optimization of segment topology and surface form for efficient illumination with freeform lens arrays

Abstract

Freeform optics allow holistic system design in both fields of imaging and illumination. In combination with lens arrays, they enable advanced applications such as aberration free imaging and beam redistribution from multiple irradiation sources. This paper describes an automated design method for freeform optical arrays in both tangential and normal directions. Optimizing the tangential layout of segments increases the solid angle of light collection and thus improves energy efficiency. Surface shapes are then computed by an iterative construction method based on Fermat's principle and Snell's law. Complex illumination with up-to 85% light collection is demonstrated experimentally.