Density estimation in optical phase space for optimizing micro-optical elements on freeform surfaces

further shape or diffuse the light distribution (e.g. in non-imaging luminaires or automotive headlights). While the geometry can be described in a parametric form by mapping the micro-optical features onto an underlying smooth freeform surface, ray-tracing an optical system composed of NURBS or polynomial B-spline surfaces for each optimization step can be costly.