Full quantum reconstruction of vortex states
  We propose a complete tomographic reconstruction of any vortex state carrying orbital angular momentum. The scheme determines the angular probability distribution of the state at different times under free evolution. To represent the quantum state we introduce a bona fide Wigner function defined on the discrete cylinder, which is the natural phase space for the pair angle-angular momentum. The feasibility of the proposal is addressed. 
I. Rigas, L. L. Sanchez-Soto, A. B. Klimov, J. Rehacek, and Z. Hradil