Automatic obscuration elimination for off-axis mirror systems.

The degree of automation in optical design has always been improving, and several human-competitive automatic lens design programs have been developed. However, to the best of our knowledge, no such work on off-axis systems has been reported, which we think is largely due to the complicated unfeasible conditions caused by obscuration. Here, we propose a model to detect and evaluate the degree of obscuration for off-axis mirror systems and also a method to automatically eliminate the obscuration by structural optimization. This effect of obscuration elimination is demonstrated by several examples. It can greatly facilitate the design of off-axis mirror systems. Particularly, the method can be applied in the search for feasible off-axis structures from on-axis ones. This work may provide insight for further study of human-competitive automatic design of off-axis systems.