Shaped Pupil Design for Future Space Telescopes

Several years ago at Princeton we invented a technique to optimize shaped pupil (SP) coronagraphs for any telescope aperture. In the last year, our colleagues at the Jet Propulsion Laboratory (JPL) invented a method to produce these non-freestanding mask designs on a substrate. These two advances allowed us to design SPs for two possible space telescopes for the direct imaging of exoplanets and disks, WFIRST-AFTA and Exo-C. In December 2013, the SP was selected along with the hybrid Lyot coronagraph for placement in the AFTA coronagraph instrument. Here we describe our designs and analysis of the SPs being manufactured and tested in the High Contrast Imaging Testbed at JPL. We also explore hybrid SP coronagraph designs for AFTA that would improve performance with minimal or no changes to the optical layout. These possibilities include utilizing a Lyot stop after the focal plane mask or applying large, static deformations to the deformable mirrors (nominally for wavefront correction) already in the system.