Investigation of optimization strategy and freeform location on multi-surface systems

The development in optical manufacture, alignment and testing has enabled the increasing use of freeform surfaces in all kinds of optical systems. The demanding system requirements need the involvement of optical surfaces that is able to provide more degrees of freedom. For better and more efficient use of the freeform surfaces, the understanding of freeform surfaces from all perspectives is necessary. We therefore study the impact of optimization strategy and freeform location on typical optical systems for varying applications. The uses of different optimization strategies, as well as the choice of locations for placing one or two freeform surfaces are considered. Their respective impacts on the final system performance are analyzed according to different aberration constitutions. By concluding all findings, we present some general rules for using and optimizing freeform surfaces in real design work. In the end, a work flow that gives instructions on how to use freeform surfaces in system design is presented.