Concave micropatterned complex optical surfaces for wide angular illumination

This work presents the development of a novel single optical component for enhancing angular illumination as well as local uniformity. Unlike a conventional single curvature lens, structured micropattern arrays on a single lens curvature can help light efficiently scattered by total internal reflection or diffraction. The illumination angle and local intensity distribution can be controlled by lens curvature and refractive index of lens material as well as the shape, size, and aspect ratio of micropattern arrays on a lens curvature. Concave micropatterned complex optical surface is fabricated by a replica molding technique. The angular illumination of concave micropatterned complex optical surface with different lens curvatures under a collimated light source is captured by CCD camera. The angular illumination improves 3.7 times wider angular illumination than that of the planar micropattern arrays.