Designing of slim optical collimator

The design of a slim LED collimator is proposed. The collimator consists of a reflector and a refractive element which exploits the phenomenon of total internal reflection. The system with the thickness of 5 mm and the diameter of 30 mm was designed. The numerical simulations based on ray-tracing method demonstrate that the collimator provides the beam divergence less than 40 at half maximum of intensity with the efficiency more than 84% for Lambertian light source of 1x1 mm. The collimator performance versus light source size and error of collimator elements positioning is investigated.