Free-form optics for illumination

Illumination optics has been the first to benefit from advances in free-form tooling mainly because of its looser requirements (on surface accuracy and finishing). In the last decade, advances in free-form surface tooling have offered the designer possibilities for which there are few theoretical design tools. The available free-form design tools are reviewed with special attention to the most powerful: the SMS 3D design method. Examples of designs done with this method are given.