Hybrid pupil mapping/masking systems for high-contrast imaging

Pupil mapping, also known as phase induced amplitude apodization or PIAA, has emerged as an interesting design concept for NASA's Terrestrial Planet Finder space telescope. However, in a previous paper it was demonstrated that diffraction effects limit the best achievable contrast to about 10 ^-5, which is 5 orders of magnitude short of the required level. Recent work by Olivier Guyon and his collaborators shows that a certain hybrid system can restore the contrast to the required level without degrading significantly the attractive throughput, achromaticity, and inner working angle advantages, In this paper, efficient computational tools are described that can be used to evaluate such designs. It is shown that a design similar to the one proposed by Guyon does indeed meet the contrast requirement.