Design of a programmable spiral phase mirror
  We designed a metallic programmable mirror for optical wavelengths made up of a large number of discrete steps which can be moved independently by actuators. The device is able to easily reshape an incident beam, imprinting on it an optical vortex with tunable topological charge and orbital angular momentum (OAM). Furthermore it is possible to generate almost arbitrary field profiles which can be used for spatial encoding. 
Fabio Antonio Bovino, Matteo Braccini, and Mario Bertolotti
physics.optics