Fast and robust technique for design of axisymmetric TIR optics in case of an extended light source

Abstract

We propose a new optimization method for computation of axisymmetric total internal reflection (TIR) optics for light-emitting diodes (LEDs). The method is designed for the general case of an extended light source, and is based on the analytical computation of an initial TIR profile for a point light source and its subsequent optimization. The distinctive feature of the proposed method is low computation time, which is a result of using in the optimization process of the adapted ray-tracing technique, based on the representation of optical surfaces by a set of truncated cones. The TIR optical element, generating a uniformly illuminated circular area with an angular size of 60°, is computed for the Lambert light source with a size of 1 × 1 mm2. The results of simulations prove the high performance of the proposed technique.