This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration, and is based on observations obtained at the Hale Telescope, Palomar Observatory, as part of a continuing collaboration between the California Institute of Technology, NASA/JPL, and Cornell University. We thank the staff of the Palomar Observatory and both the JPL and Caltech Palomar Adaptive Optics (PALAO) teams, as well as our colleagues at JDS Uniphase, where our vortex masks are manufactured.

Author Contributions All authors contributed equally to this work.