Unified matrix representation for spin and orbital angular momentum in partially coherent beams

A matrix representation is introduced for stationary beam-like light fields\nthat allows for simultaneous treatment of the orbital angular momentum (OAM)\nand the second-order state of spatial coherence. This Coherence-OAM matrix is a\ncounterpart of the 2 x 2 beam Coherence-polarization matrix in a Cartesian\npolarization basis or Coherence-spin angular momentum (SAM) matrix in a\ncircular polarization basis. The general properties of the Coherence-OAM matrix\nare discussed and then the Coherence-SAM-OAM matrix is introduced as a unifying\nentity for treating beams with any coherence, spin and orbital angular momentum\nstates.\n