FrogEye, the Quantum Coronagraphic mask. The Photon Orbital Angular   Momentum and its applications to Astronomy
  We propose to realize an optical device based on the properties of photon orbital angular momentum (POAM) to detect the presence of closeby faint companions in double systems using Laguerre-Gaussian (L-G) modes of the light. We test also the possibility of using L-G modes to build coronagraph mask. We realized in the laboratory a prototype using a blazed l=1 hologram to simulate the separation between two stars, as observed with a telescope, in Laguerre-Gaussian modes. 
F. Tamburini, G. Umbriaco, G. Anzolin, C. Barbieri and A. Bianchini