Applying the composing method and aberration theory for collimating systems design

We demonstrate a simple design method to be applied in designing of LED collimating systems. In the first stage, we have considered several zones in a lighting beam and analyze their aberration properties, in the second stage we combine zones into a whole system taking into account the possible residual divergence of the beam. Compared to the analogous design methods, the method gives a possibility to choose the size of zones more consciously and evaluate the divergence without complicated and huge computations. Additionally, the derived equations give us an opportunity of understanding possible collimating properties of a system before the design. An example is given of a highly efficient collimating lens working with a 1 mm ×1 mm Lambertian LED. According to the simulation result, the optical efficiency of about 90% of light flux inside the angle of ±5 deg is achieved.