We describe a method to observe dim exoplanets that eliminates light from the parent star across the entire exit pupil without sacrificing light from the planet by use of a vortex mask of topological charge m=2.
© 2005 Optical Society of America
Gregory Foo, David M. Palacios, and Grover A. Swartzlander, Jr., "Optical vortex coronagraph," Opt. Lett. 30, 3308-3310 (2005)