Eighth‐Order Image Masks for Terrestrial Planet Finding

We describe a new series of band-limited image masks for coronagraphy that are insensitive to tip-tilt errors and other low spatial frequency optical aberrations. For a modest cost in throughput, these "eighth-order" masks would allow the Terrestrial Planet Finder Coronagraph ( TPF-C ) to operate with a pointing accuracy no better than that of the Hubble Space Telescope . We also provide eighth-order notch filter masks that offer the same robustness to pointing errors combined with more manageable construction tolerances: binary masks and sampled graded masks with moderate optical density requirements.