Observation of Interaction of Spin and Intrinsic Orbital Angular   Momentum of Light
  Interaction of spin and intrinsic orbital angular momentum of light is observed, as evidenced by length-dependent rotations of both spatial patterns and optical polarization in a cylindrically-symmetric isotropic optical fiber. Such rotations occur in straight few-mode fiber when superpositions of two modes with parallel and anti-parallel orientation of spin and intrinsic orbital angular momentum (IOAM=$2\hslash$) are excited, resulting from a degeneracy splitting of the propagation constants of the modes. 
Dashiell L. P. Vitullo, Cody C. Leary, Patrick Gregg, Roger A. Smith,   Dileep V. Reddy, Siddharth Ramachandran, and Michael...
physics.optics quant-ph