Electromagnetic Spin-Orbit Interactions via Scattering
  The longitudinal components of orthogonal-circularly polarized fields carry a phase singularity that changes sign depending on the polarization handedness. The addition of orbital angular momentum adds to or cancels this singularity and results in polarization-dependent scattering through round and square apertures, which we demonstrate analytically, numerically, and experimentally. By preparing the incident polarization and arranging the configuration of sub-wavelength apertures, we produce shadow-side scattered fields with arbitrary phase vorticity. 
L.T. Vuong, A.J.L. Adam, J.M. Brok, M. A. Seo, D. S. Kim, P.C.M.   Planken, H.P. Urbach