Management of the orbital angular momentum of vortex beams in a   quadratic nonlinear interaction
  Light intensity control of the orbital angular momentum of the fundamental beam in a quadratic nonlinear process is theoretically and numerically presented. In particular we analyzed a seeded second harmonic generation process in presence of orbital angular momentum of the interacting beams due both to on axis and off axis optical vortices. Examples are proposed and discussed. 
Fabio A. Bovino, Matteo Braccini, Mario Bertolotti, Concita Sibilia
physics.optics