  Illumination is the deliberate utilization of light to realize practical or
aesthetic effects. The designers combine with the environmental considerations,
energy-saving goals, and technology advances with fundamental physics to
develop lighting solutions to satisfy all of our ever-changing needs. Achieving
highly efficient and precise control of the energy output of light sources
while maintaining compact optical structures is the ultimate goal of
illumination design. To realize miniaturized and lightweight luminaires, the
design process must consider the extents of light sources. However, the
illumination design for extended sources is still a challenging and unsolved
problem. Here, we propose a method to design ultra-performance illumination
optics enabled by freeform optical surfaces. The proposed method is very
general with no limitations of far-field approximation and Lambertian
luminescent property. We demonstrate the feasibility and efficiency of the
proposed method by designing several freeform lenses realizing accurate and
highly efficient illumination control as well as ultra-compact structures.
