A quantum-field-theory approach is put forward to generalize the concept of classical spatial light beams carrying orbital angular momentum to the single-photon level. This quantization framework is carried out both in the paraxial and nonparaxial regimes. Upon extension to the optical phase space, closed-form expressions are found for a photon Wigner representation describing transformations on the orbital Poincaré sphere of unitarily related families of paraxial spatial modes. © 2006 The American Physical Society.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 1 Jan 2006|