BISRAT GIRMA

Recent energy efficient illumination advancements have capitalized on using light-emitting diodes (LEDs) in combination with freeform lenses. However, the available freeform lens design methods are application specific. In addition, manufacturing of this class of optics is challenging. In this work, considering manufacturing constraints, we apply a customized algorithm to design freeform lenses for (1) transforming LED radiation into a uniform rectangular illumination pattern and (2) shaping collimated LED light beams into complex image target irradiance distributions. The algorithm is based on a numerical solution of the elliptic Monge-Ampère equation. Then, we proposed manufacturing these lenses using a modified ink-jet 3D printing technology called Printoptical technology. The demonstrated optical performance of printed lenses, exhibiting surface roughness of RMS=10±2