Survey of the four-mirror freeform imager solution space

We present the results and methods of a survey of the four-mirror freeform imager solution space. This survey is a grid search over the parameters that remain after reducing the solution space’s degrees of freedom using first-, second-, and third-order aberration theory. We then optimize the systems’ higher-order surface shapes through sixth-order. Finally, we discuss general trends in the systems’ performance versus volume and etendue and their utility in trade studies.