Efficient and compact freeform optics design for customized LED lighting

Adoption of LED lighting products have many advantages such as energy conservation and environmental protection. But the luminescent characteristics of LEDs cannot provide satisfactory lighting solutions to meet the requirements of today’s sophisticated applications. Freeform optics constitutes a new technique for regulating the energy output of LEDs into a customized form. However, many freeform optical elements are designed to be bulky since the point-like sources assumption. The designs that consider the spatial extents of LEDs usually have poorly controlled light patterns or low efficiencies. Here, we propose a very robust design method based on spatially variant convolution for 4D light field tailoring, which enables high-performing freeform illumination optics with small sizes. The proposed method is holistic that is suitable for various kinds of design requirements with no limitations of far-field approximation and Lambertian luminescent property. Several design examples including fabricated lenses and experimental tests are presented. The results realize compact, low-cost, and highly efficient freeform optics with customized lighting solutions. We expect that the proposed work can promote the research on enhancing the emission quality of LEDs and generating artificial light for application-specific lighting systems.